38652 Federal Register / Vol. 86, No. 138 / Thursday, July 22, 2021 / Proposed Rules 

1 62 FR 38652. 

2For a given air pollutant, ‘‘primary’’ NAAQS are 

those determined by the EPA as requisite to protect 

the public health, allowing an adequate margin of 

safety, and ‘‘secondary’’ standards are those 

determined by the EPA as requisite to protect the 

public welfare from any known or anticipated 

adverse effects associated with the presence of such 

air pollutant in the ambient air. See CAA section 

109(b). 

3 40 CFR 50.7. 

4 71 FR 61144. 

5 78 FR 3086. 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R09–OAR–2021–0260; FRL–8644–02– 

R9] 

Partial Approval and Partial 

Disapproval of Air Quality 

Implementation Plans; California; San 

Joaquin Valley Serious Area and 

Section 189(d) Plan for Attainment of 

the 1997 Annual PM2.5 NAAQS 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is proposing to approve 

in part and disapprove in part portions 

of a state implementation plan (SIP) 

revision submitted by the State of 

California to meet Clean Air Act (CAA 

or ‘‘Act’’) requirements for the 1997 

annual fine particulate matter (PM2.5) 

national ambient air quality standards 

(NAAQS or ‘‘standards’’) in the San 

Joaquin Valley PM2.5 nonattainment 

area. Specifically, the EPA is proposing 

to approve the 2013 base year emissions 

inventories in the submitted SIP 

revisions. Because the area did not 

attain by the State’s projected 

attainment date of December 31, 2020, 

the EPA is proposing to disapprove the 

attainment demonstration and related 

elements, including the comprehensive 

precursor demonstration, five percent 

annual emission reductions 

demonstration, best available control 

measures (BACM) demonstration, 

reasonable further progress (RFP) 

demonstration, quantitative milestone 

demonstration, and contingency 

measures. The EPA is also proposing to 

disapprove the motor vehicle emission 

budgets in the plan as not meeting the 

requirements of the CAA and EPA 

regulations. 

DATES: Any comments on this proposal 

must be received by August 23, 2021. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R09– 

OAR–2021–0260 at https://

www.regulations.gov. For comments 

submitted at Regulations.gov, follow the 

online instructions for submitting 

comments. Once submitted, comments 

cannot be edited or removed from 

Regulations.gov. The EPA may publish 

any comment received to its public 

docket. Do not submit electronically any 

information you consider to be 

Confidential Business Information (CBI) 

or other information whose disclosure is 

restricted by statute. Multimedia 

submissions (e.g., audio or video) must 

be accompanied by a written comment. 

The written comment is considered the 

official comment and should include 

discussion of all points you wish to 

make. The EPA will generally not 

consider comments or comment 

contents located outside of the primary 

submission (i.e., on the web, cloud, or 

other file sharing system). For 

additional submission methods, please 

contact the person identified in the FOR

FURTHER INFORMATION CONTACT section. 

For the full EPA public comment policy, 

information about CBI or multimedia 

submissions, and general guidance on 

making effective comments, please visit 

https://www.epa.gov/dockets/ 

commenting-epa-dockets. If you need 

assistance in a language other than 

English or if you are a person with 

disabilities who needs a reasonable 

accommodation at no cost to you, please 

contact the person identified in the FOR

FURTHER INFORMATION CONTACT section. 

FOR FURTHER INFORMATION CONTACT: 

Ashley Graham, Air Planning Office 

(ARD–2), EPA Region IX, 75 Hawthorne 

Street, San Francisco, CA 94105, (415) 

972–3877, or by email at 

graham.ashleyr@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this document, ‘‘we,’’ ‘‘us,’’ 

and ‘‘our’’ refer to the EPA. 

Table of Contents 

I. Background for Proposed Action 

A. PM2.5 NAAQS 

B. San Joaquin Valley PM2.5 Designations, 

Classifications, and SIP Revisions 

II. Summary and Completeness Review of the 

San Joaquin Valley PM2.5 Plan 

A. 2018 PM2.5 Plan 

B. Valley State SIP Strategy 

C. District Rule 4901 

III. Clean Air Act Requirements for Serious 

PM2.5 Areas That Fail To Attain 

IV. Review of the San Joaquin Valley PM2.5

Plan 

A. Emissions Inventories 

B. PM2.5 Precursors 

C. Attainment Plan Control Strategy 

D. Attainment Demonstration and 

Modeling 

E. Reasonable Further Progress and 

Quantitative Milestones 

F. Contingency Measures 

G. Motor Vehicle Emission Budgets 

H. Nonattainment New Source Review 

Requirements Under CAA Section 189(e) 

V. Proposed Action 

A. Effect of Finalizing the Proposed 

Disapproval Actions 

VI. Statutory and Executive Order Reviews 

I. Background for Proposed Action 

A. PM2.5 NAAQS 

Under section 109 of the CAA, the 

EPA has established NAAQS for certain 

pervasive air pollutants (referred to as 

‘‘criteria pollutants’’) and conducts 

periodic reviews of the NAAQS to 

determine whether they should be 

revised or whether new NAAQS should 

be established. 

On July 18, 1997, the EPA revised the 

NAAQS for particulate matter by 

establishing new NAAQS for particles 

with an aerodynamic diameter less than 

or equal to a nominal 2.5 micrometers 

(PM2.5).1 The EPA established primary 

and secondary annual and 24-hour 

standards for PM2.5.2 The annual 

primary and secondary standards were 

set at 15.0 micrograms per cubic meter 

(mg/m3), based on a three-year average of 

annual mean PM2.5 concentrations, and 

the 24-hour primary and secondary 

standards were set at 65 mg/m3, based on 

the three-year average of the 98th 

percentile of 24-hour PM2.5

concentrations at each monitoring site 

within an area.3 Collectively, we refer 

herein to the 1997 annual and 24-hour 

PM2.5 NAAQS as the ‘‘1997 PM2.5

NAAQS’’ or ‘‘1997 PM2.5 standards.’’ 

On October 17, 2006, the EPA revised 

the level of the 24-hour PM2.5 NAAQS 

to 35 mg/m3,4 and on January 15, 2013, 

the EPA revised the level of the primary 

annual PM2.5 NAAQS to 12.0 mg/m3.5

Even though the EPA has lowered the 

24-hour and annual PM2.5 standards, the 

1997 PM2.5 standards remain in effect. 

The EPA established these standards 

after considering substantial evidence 

from numerous health studies 

demonstrating that serious health effects 

are associated with exposures to PM2.5

concentrations above these levels. 

Epidemiological studies have shown 

statistically significant correlations 

between elevated PM2.5 levels and 

premature mortality. Other important 

health effects associated with PM2.5

exposure include aggravation of 

respiratory and cardiovascular disease 

(as indicated by increased hospital 

admissions, emergency room visits, 

absences from school or work, and 

restricted activity dates), changes in 

lung function and increased respiratory 

symptoms, and new evidence for more 

subtle indicators of cardiovascular 

health. Individuals particularly 

sensitive to PM2.5 exposure include 


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6EPA, Air Quality Criteria for Particulate Matter, 

No. EPA/600/P–99/002aF and EPA/600/P–99/ 

002bF, October 2004. 

7For example, see 72 FR 20586, 20589 (April 25, 

2007). 

8 70 FR 944 (January 5, 2005). 

9 40 CFR 81.305. 

10For a precise description of the geographic 

boundaries of the San Joaquin Valley nonattainment 

area, see 40 CFR 81.305. 

11CAA sections 172(a)(2), 172(c)(1), 172(c)(2), 

and 172(c)(9). 

12 76 FR 69896, n. 2 (November 9, 2011). 

13 Id. at 69924. 

14 Id. 

15Natural Resources Defense Council v. EPA, 706 

F.3d. 428 (D.C. Cir. 2013) (‘‘NRDC’’). In NRDC, the 

court held that the EPA erred in implementing the 

1997 PM2.5 standards solely pursuant to the general 

implementation requirements of subpart 1, without 

also considering the requirements specific to 

nonattainment areas for particles less than or equal 

to 10 mm in diameter (PM10) in subpart 4, part D 

of title I of the CAA. The court reasoned that the 

plain meaning of the CAA requires implementation 

of the 1997 PM2.5 standards under subpart 4 

because PM2.5 falls within the statutory definition 

of PM10 and is thus subject to the same statutory 

requirements as PM10. The court remanded the rule, 

without vacatur, and instructed the EPA ‘‘to 

repromulgate these rules pursuant to Subpart 4 

consistent with this opinion.’’ 

16 79 FR 31566. 

17 80 FR 18528 (April 7, 2015). 

18 81 FR 6936. California’s request for extension 

of the Serious Area attainment date for the San 

Joaquin Valley accompanied its Serious Area 

attainment plan for the 1997 PM2.5 NAAQS and 

related motor vehicle emission budgets, submitted 

June 25, 2015 and August 13, 2015, respectively. 

19 81 FR 69396. The EPA did not finalize the 

actions proposed on February 9, 2016, with respect 

to the submitted Serious area plan. Id. at 69400. 

20 81 FR 84481. 

21 83 FR 62720. 

22 Id. at 62723. 

older adults, people with heart and lung 

disease, and children.6

Sources can emit PM2.5 directly into 

the atmosphere as a solid or liquid 

particle (primary PM2.5 or direct PM2.5), 

or PM2.5 can form in the atmosphere 

(secondary PM2.5) as a result of various 

chemical reactions from precursor 

emissions of nitrogen oxides (NOX), 

sulfur oxides (SOX), volatile organic 

compounds (VOC), and ammonia.7

B. San Joaquin Valley PM2.5

Designations, Classifications, and SIP 

Revisions 

Following promulgation of a new or 

revised NAAQS, the EPA is required 

under CAA section 107(d) to designate 

areas throughout the nation as attaining 

or not attaining the NAAQS. Effective 

April 5, 2005, the EPA established the 

initial air quality designations for the 

1997 annual and 24-hour PM2.5 NAAQS, 

using air quality monitoring data for the 

three-year periods of 2001–2003 and 

2002–2004.8 The EPA designated the 

San Joaquin Valley as nonattainment for 

both the 1997 annual PM2.5 NAAQS 

(15.0 mg/m3) and the 1997 24-hour PM2.5

NAAQS (65 mg/m3).9

The San Joaquin Valley PM2.5

nonattainment area encompasses over 

23,000 square miles and includes all or 

part of eight counties: San Joaquin, 

Stanislaus, Merced, Madera, Fresno, 

Tulare, Kings, and the valley portion of 

Kern.10 The area is home to four million 

people and is one of the nation’s leading 

agricultural regions. Stretching over 250 

miles from north to south and averaging 

80 miles wide, it is partially enclosed by 

the Coast Mountain range to the west, 

the Tehachapi Mountains to the south, 

and the Sierra Nevada range to the east. 

Under State law, the San Joaquin Valley 

Unified Air Pollution Control District 

(SJVUAPCD or ‘‘District’’) has primary 

responsibility for developing plans to 

provide for attainment of the NAAQS in 

this area. The District works 

cooperatively with the California Air 

Resources Board (CARB) in preparing 

attainment plans. Authority for 

regulating sources under state 

jurisdiction in the San Joaquin Valley is 

split under State law between the 

District, which has responsibility for 

regulating stationary and most area 

sources, and CARB, which has 

responsibility for regulating most 

mobile sources. 

Within three years of the effective 

date of designations, states with areas 

designated as nonattainment for the 

1997 PM2.5 NAAQS were required to 

submit SIP revisions that, among other 

things, provided for implementation of 

reasonably available control measures 

(RACM), RFP, attainment of the 

standards as expeditiously as 

practicable but no later than five years 

from the nonattainment designation (in 

this instance, no later than April 5, 

2010) unless the state justified an 

attainment date extension of up to five 

years, and contingency measures.11

Between 2007 and 2011, California 

submitted six SIP revisions to address 

nonattainment area planning 

requirements for the 1997 PM2.5 NAAQS 

in the San Joaquin Valley,12 which we 

refer to collectively as the ‘‘2008 PM2.5

Plan.’’ On November 9, 2011, the EPA 

approved the portions of the 2008 PM2.5

Plan, as revised in 2009 and 2011, that 

addressed attainment of the 1997 PM2.5

NAAQS in the San Joaquin Valley PM2.5

nonattainment area, except for the 

attainment contingency measures, 

which we disapproved.13 We also 

granted the State’s request to extend the 

attainment deadline for the 1997 PM2.5

NAAQS in the San Joaquin Valley to 

April 5, 2015.14

Following a January 4, 2013 decision 

of the U.S. Court of Appeals for the D.C. 

Circuit (‘‘D.C. Circuit’’) remanding the 

EPA’s 2007 implementation rule for the 

1997 PM2.5 NAAQS,15 the EPA 

published a final rule on June 2, 2014, 

classifying the San Joaquin Valley, 

among other areas, as a Moderate 

nonattainment area for the 1997 PM2.5

NAAQS under subpart 4, part D of title 

I of the Act.16

Effective May 7, 2015, the EPA 

reclassified the San Joaquin Valley as a 

Serious nonattainment area for the 1997 

PM2.5 NAAQS based on our 

determination that the area could not 

practicably attain these NAAQS by the 

April 5, 2015 attainment date.17 Upon 

reclassification as a Serious area, the 

San Joaquin Valley became subject to a 

December 31, 2015 deadline under CAA 

section 188(c)(2) to attain the 1997 PM2.5

NAAQS. On February 9, 2016, the EPA 

proposed to grant the State’s request for 

extensions of the December 31, 2015 

attainment date under CAA section 

188(e), to December 31, 2018, for the 

1997 24-hour PM2.5 NAAQS, and to 

December 31, 2020, for the 1997 annual 

PM2.5 NAAQS in the San Joaquin 

Valley.18 However, on October 6, 2016, 

after considering public comments, the 

EPA denied California’s request for 

these extensions of the attainment 

dates.19 Consequently, on November 23, 

2016, the EPA determined that the San 

Joaquin Valley had failed to attain the 

1997 PM2.5 NAAQS by the December 31, 

2015 Serious area attainment date.20

This determination triggered a 

requirement for California to submit, by 

December 31, 2016, a revised PM2.5

attainment plan for the 1997 PM2.5

NAAQS for the San Joaquin Valley that 

satisfies the requirements of CAA 

section 189(d). 

On December 6, 2018, the EPA 

determined that California had failed to 

submit a complete Serious area and 

section 189(d) attainment plan for the 

1997 PM2.5 NAAQS, among other 

required SIP submissions for the San 

Joaquin Valley, by the submittal 

deadline.21 This finding, which became 

effective on January 7, 2019, triggered 

clocks under CAA section 179(a) for the 

application of emissions offset sanctions 

18 months after the finding and 

highway funding sanctions six months 

thereafter, unless the EPA affirmatively 

determines that the State has submitted 

a complete SIP addressing the identified 

deficiencies.22 The finding also 

triggered the obligation under CAA 

section 110(c) on the EPA to promulgate 

a federal implementation plan no later 

than two years after the finding, unless 

the State has submitted, and the EPA 

has approved, the required SIP 


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23 Id. 

24Letter dated May 9, 2019, from Richard Corey, 

Executive Officer, CARB, to Mike Stoker, Regional 

Administrator, EPA Region 9. 

25Letter dated June 24, 2020, from Elizabeth J. 

Adams, Director, Air and Radiation Division, EPA 

Region IX, to Richard W. Corey, Executive Officer, 

CARB, Subject: ‘‘RE: Completeness Finding for 

State Implementation Plan (SIP) Submissions for 

San Joaquin Valley for the 1997, 2006, and 2012 

Fine Particulate Matter (PM2.5) National Ambient 

Air Quality Standards (NAAQS) and Termination of 

Clean Air Act (CAA) Sanction Clocks.’’ 

26The 2018 PM2.5 Plan was developed jointly by 

CARB and the District. 

27Letter dated May 9, 2019, from Richard Corey, 

Executive Officer, CARB, to Mike Stoker, Regional 

Administrator, EPA Region 9. The letter clarifies 

that the 2018 PM2.5 Plan supersedes past submittals 

to the EPA that the agency has not yet acted on for 

the 1997 standards, including the 2015 Plan for the 

1997 Standard (submitted by CARB on June 25, 

2015) and motor vehicle emission budgets 

(submitted by CARB August 13, 2015). The EPA 

previously acted on those portions of the ‘‘2018 

Plan for the 1997, 2006, and 2012 PM2.5 Standards’’ 

and the ‘‘San Joaquin Valley Supplement to the 

2016 State Strategy for the State Implementation 

Plan’’ that pertain to the 2006 PM2.5 NAAQS (85 FR 

44192, July 22, 2020), and is not, at this time, 

proposing to act on those portions that pertain to 

the 1997 24-hour PM2.5 NAAQS or the 2012 annual 

PM2.5 NAAQS. We intend to act on these portions 

of the submitted SIP revisions in subsequent 

rulemakings. 

28Letter dated July 19, 2019, from Richard W. 

Corey, Executive Officer, CARB, to Mike Stoker, 

Regional Administrator, EPA Region 9. 

29Chapter 6 (‘‘Demonstration of Federal 

Requirements for the 2006 PM2.5 Standard: Serious 

Plan and Extension Request’’) and Chapter 7 

(‘‘Demonstration of Federal Requirements for the 

2012 PM2.5 Standard’’) of the 2018 PM2.5 Plan 

pertain to the 2006 PM2.5 NAAQS and the 2012 

PM2.5 NAAQS, respectively. The EPA previously 

acted on those portions of the Plan that pertain to 

the 2006 PM2.5 NAAQS (85 FR 44192, July 22, 2020) 

and intends to act on those portions that pertain to 

the 1997 24-hour PM2.5 NAAQS and 2012 PM2.5

NAAQS in separate rulemakings. 

30Letter dated December 11, 2019, from Richard 

Corey, Executive Officer, CARB, to Mike Stoker, 

Regional Administrator, EPA Region 9, transmitting 

the CARB Staff Report [on the 2018 PM2.5 Plan]. The 

CARB Staff Report includes CARB’s review of, 

among other things, the 2018 PM2.5 Plan’s control 

strategy and attainment demonstration. 

31CARB Resolution 19–1, ‘‘2018 PM2.5 State 

Implementation Plan for the San Joaquin Valley,’’ 

January 24, 2019, and SJVUAPCD Governing Board 

Resolution 18–11–16, ‘‘Adopting the [SJVUAPCD] 

2018 Plan for the 1997, 2006, and 2012 PM2.5

Standards,’’ November 15, 2018. 

32Appendix H to 2018 PM2.5 Plan, submitted 

February 11, 2020 via the EPA State Planning 

Electronic Collaboration System. Following the 

identification of a transcription error in the RFP 

tables of Appendix H, on February 11, 2020, the 

State submitted a revised version of Appendix H 

that corrects the transcription error and provides 

additional information on the RFP demonstration. 

All references to Appendix H in this proposed rule 

are to the revised version submitted on February 11, 

2020, which replaces the version submitted with 

the 2018 PM2.5 Plan on May 10, 2019. 

33SJVUAPCD, ‘‘Notice of Public Hearing for 

Adoption of Proposed 2018 PM2.5 Plan for the 1997, 

2006, and 2012 Standards,’’ October 16, 2018, and 

SJVUAPCD Governing Board Resolution 18–11–16. 

submittal.23 CARB submitted a revised 

attainment plan for the 1997 PM2.5

NAAQS, among other submissions, on 

May 10, 2019.24 This SIP revision is the 

subject of this proposal. On June 24, 

2020, the EPA issued a letter finding the 

submittal complete and terminating the 

sanctions clocks under CAA section 

179(a).25

II. Summary and Completeness Review 

of the San Joaquin Valley PM2.5 Plan 

The EPA is proposing action on 

portions of three SIP revisions 

submitted by CARB to meet CAA 

requirements for the 1997 annual PM2.5

NAAQS in the San Joaquin Valley. 

Specifically, the EPA is proposing to act 

on those portions of the following two 

plan submissions that pertain to the 

1997 annual PM2.5 NAAQS: The ‘‘2018 

Plan for the 1997, 2006, and 2012 PM2.5

Standards,’’ adopted by the SJVUAPCD 

on November 15, 2018, and by CARB on 

January 24, 2019 (‘‘2018 PM2.5 Plan’’); 26

and the ‘‘San Joaquin Valley 

Supplement to the 2016 State Strategy 

for the State Implementation Plan,’’ 

adopted by CARB on October 25, 2018 

(‘‘Valley State SIP Strategy’’). CARB 

submitted the 2018 PM2.5 Plan and 

Valley State SIP Strategy to the EPA as 

a revision to the California SIP on May 

10, 2019.27 We refer to these two SIP 

submissions collectively as the ‘‘SJV 

PM2.5 Plan’’ or ‘‘Plan.’’ 

The EPA is also proposing action on 

2019 amendments to the regional air 

district residential wood-burning rule, 

SJVUAPCD Rule 4901, ‘‘Wood Burning 

Fireplaces and Wood Burning Heaters’’ 

(‘‘Rule 4901’’), adopted by the 

SJVUAPCD on June 20, 2019, and by 

CARB on July 19, 2019.28 These 

amendments include a contingency 

measure (in section 5.7.3 of the 

amended rule) that applies to the 1997 

annual PM2.5 NAAQS. 

The SJV PM2.5 Plan addresses the 

Serious area and CAA section 189(d) 

requirements for the 1997 PM2.5 NAAQS 

in the San Joaquin Valley, including the 

State’s demonstration that the area will 

attain the 1997 annual PM2.5 NAAQS by 

December 31, 2020. In this proposal, the 

EPA is proposing to act only on those 

portions of the SJV PM2.5 Plan that 

pertain to the 1997 annual PM2.5

NAAQS. The EPA intends to act on the 

portions of the SJV PM2.5 Plan that 

pertain to the 1997 24-hour PM2.5

NAAQS and subsequent PM2.5 NAAQS 

in separate rulemakings. 

CAA sections 110(a)(1) and (2) and 

110(l) require each state to provide 

reasonable public notice and 

opportunity for public hearing prior to 

the adoption and submission of a SIP or 

SIP revision to the EPA. To meet this 

requirement, every SIP submission 

should include evidence that adequate 

public notice was given and that an 

opportunity for a public hearing was 

provided consistent with the EPA’s 

implementing regulations in 40 CFR 

51.102. 

CAA section 110(k)(1)(B) requires the 

EPA to determine whether a SIP 

submission is complete within 60 days 

of receipt. This section also provides 

that any plan that the EPA has not 

affirmatively determined to be complete 

or incomplete will become complete by 

operation of law six months after the 

date of submission. The EPA’s SIP 

completeness criteria are found in 40 

CFR part 51, Appendix V. 

A. 2018 PM2.5 Plan 

The following portions of the 2018 

PM2.5 Plan and related support 

documents address both the Serious 

area requirements in CAA section 189(b) 

and the CAA section 189(d) 

requirements for the 1997 annual PM2.5

NAAQS in the San Joaquin Valley: (i) 

Chapter 4 (‘‘Attainment Strategy for 

PM2.5’’), (ii) Chapter 5 (‘‘Demonstration 

of Federal Requirements for 1997 PM2.5

Standards’’); 29 (iii) numerous 

appendices to the 2018 PM2.5 Plan; (iv) 

CARB’s ‘‘Staff Report, Review of the San 

Joaquin Valley 2018 Plan for the 1997, 

2006, and 2012 PM2.5 Standards,’’ 

release date December 21, 2018 (‘‘CARB 

Staff Report’’); 30 and (v) the State’s and 

District’s board resolutions adopting the 

2018 PM2.5 Plan (CARB Resolution 19– 

1 and SJVUAPCD Governing Board 

Resolution 18–11–16).31

The appendices to the 2018 PM2.5

Plan that address the requirements for 

the 1997 annual PM2.5 NAAQS include: 

(i) Appendix A (‘‘Ambient PM2.5 Data 

Analysis’’); (ii) Appendix B (‘‘Emissions 

Inventory’’); (iii) Appendix C 

(‘‘Stationary Source Control Measure 

Analyses’’); (iv) Appendix D (‘‘Mobile 

Source Control Measure Analyses’’); (v) 

Appendix G (‘‘Precursor 

Demonstration’’); (vi) Appendix H 

(‘‘RFP, Quantitative Milestones, and 

Contingency’’); 32 (vii) Appendix I 

(‘‘New Source Review and Emission 

Reduction Credits’’); (viii) Appendix J 

(‘‘Modeling Emission Inventory’’); (ix) 

Appendix K (‘‘Modeling Attainment 

Demonstration’’); and (x) Appendix L 

(‘‘Modeling Protocol’’). 

The District provided public notice 

and opportunity for public comment 

prior to its November 15, 2018 public 

hearing on and adoption of the 2018 

PM2.5 Plan.33 CARB also provided 

public notice and opportunity for public 

comment prior to its January 24, 2019 

public hearing on and adoption of the 


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34CARB, ‘‘Notice of Public Meeting to Consider 

the 2018 PM2.5 State Implementation Plan for the 

San Joaquin Valley,’’ December 21, 2018, and CARB 

Resolution 19–1. 

35CARB, ‘‘Board Meeting Comments Log,’’ March 

29, 2019; J&K Court Reporting, LLC, ‘‘Meeting, State 

of California Air Resources Board,’’ January 24, 

2019 (transcript of CARB’s public hearing), and 

2018 PM2.5 Plan, Appendix M (‘‘Summary of 

Significant Comments and Responses’’). 

36The EPA has approved certain commitments 

made by CARB in the 2016 State Strategy for 

purposes of attaining the ozone NAAQS in the San 

Joaquin Valley and South Coast ozone 

nonattainment areas (for example, see 84 FR 3302 

(February 12, 2019) and 84 FR 52005 (October 1, 

2019)) and for attaining the 2006 PM2.5 NAAQS in 

the San Joaquin Valley (85 FR 44192 (July 22, 

2020)). 

37CARB Resolution 17–7, ‘‘2016 State Strategy for 

the State Implementation Plan,’’ March 23, 2017, 

6–7. 

38Letter dated May 9, 2019, from Richard Corey, 

Executive Officer, CARB, to Mike Stoker, Regional 

Administrator, EPA Region 9, 2. 

39For example, Table 2 (proposed mobile source 

measures and schedule), Table 3 (emissions 

reductions from proposed mobile source measures), 

and Table 4 (summary of emission reduction 

measures) of the Valley State SIP Strategy 

correspond to tables 4–8, 4–9, and 4–7, 

respectively, of the 2018 PM2.5 Plan, Chapter 4. 

40CARB Resolution 18–49, ‘‘San Joaquin Valley 

Supplement to the 2016 State Strategy for the State 

Implementation Plan,’’ October 25, 2018, 5. 

41CARB, ‘‘Notice of Public Meeting to Consider 

the San Joaquin Valley Supplement to the 2016 

State Strategy for the State Implementation Plan,’’ 

September 21, 2018, and CARB Resolution 18–49. 

42CARB, ‘‘Board Meeting Comments Log,’’ 

November 2, 2018 and compilation of written 

comments; and J&K Court Reporting, LLC, 

‘‘Meeting, State of California Air Resources Board,’’ 

October 25, 2018 (transcript of CARB’s public 

hearing). 

43 2018 PM2.5 Plan, Appendix H, H–25. 

44Letter dated July 19, 2019 from Richard W. 

Corey, Executive Officer, CARB, to Mike Stoker, 

Regional Administrator, EPA Region 9. 

45 85 FR 44206 (July 22, 2020) (final approval of 

Rule 4901); 85 FR 1131, 1132–33 (January 9, 2020) 

(proposed approval of Rule 4901). 

46 85 FR 1131, 1132–33. 

47 85 FR 1131 (January 9, 2020) (proposed 

approval of revised Rule 4901) and 85 FR 44206 

(July 22, 2020) (final approval of revised Rule 4901). 

2018 PM2.5 Plan.34 The SIP submission 

includes proof of publication of notices 

for the respective public hearings. It also 

includes copies of the written and oral 

comments received during the State’s 

and District’s public review processes 

and the agencies’ responses thereto.35

Therefore, we find that the 2018 PM2.5

Plan meets the procedural requirements 

for public notice and hearing in CAA 

sections 110(a) and 110(l) and 40 CFR 

51.102. The 2018 PM2.5 Plan became 

complete by operation of law on 

November 10, 2019. 

B. Valley State SIP Strategy 

CARB developed the ‘‘Revised 

Proposed 2016 State Strategy for the 

State Implementation Plan’’ (‘‘2016 

State Strategy’’) to support attainment 

planning in the San Joaquin Valley and 

Los Angeles-South Coast Air Basin 

(‘‘South Coast’’) ozone nonattainment 

areas.36 In its resolution adopting the 

2016 State Strategy (CARB Resolution 

17–7), the Board found that the 2016 

State Strategy would achieve 6 tons per 

day (tpd) of NOX emissions reductions 

and 0.1 tpd of direct PM2.5 emissions 

reductions in the San Joaquin Valley by 

2025 and directed CARB staff to work 

with SJVUAPCD to identify additional 

reductions from sources under District 

regulatory authority as part of a 

comprehensive plan to attain the PM2.5

standards for the San Joaquin Valley 

and to return to the Board with a 

commitment to achieve additional 

emission reductions from mobile 

sources.37

CARB responded to this resolution by 

developing and adopting the ‘‘San 

Joaquin Valley Supplement to the 2016 

State Strategy for the State 

Implementation Plan’’ (‘‘Valley State 

SIP Strategy’’) to support the 2018 PM2.5

Plan. The State’s May 10, 2019 SIP 

submission incorporates by reference 

the Valley State SIP Strategy as adopted 

by CARB on October 25, 2018 and 

submitted to the EPA on November 16, 

2018.38

The Valley State SIP Strategy includes 

an ‘‘Introduction’’ (Chapter 1), a chapter 

on ‘‘Measures’’ (Chapter 2), and a 

‘‘Supplemental State Commitment from 

the Proposed State Measures for the 

Valley’’ (Chapter 3). Much of the 

content of the Valley State SIP Strategy 

is reproduced in Chapter 4 (‘‘Attainment 

Strategy for PM2.5’’) of the 2018 PM2.5

Plan.39 The Valley State SIP Strategy 

also includes CARB Resolution 18–49, 

which, among other things, commits 

CARB to achieve specific amounts of 

NOX and PM2.5 emissions reductions by 

specific years, for purposes of attaining 

the PM2.5 NAAQS in the San Joaquin 

Valley.40

CARB provided the required public 

notice and opportunity for public 

comment prior to its October 25, 2018 

public hearing on and adoption of the 

Valley State SIP Strategy.41 The SIP 

submission includes proof of 

publication of the public notice for this 

public hearing. It also includes copies of 

the written and oral comments received 

during the State’s public review process 

and CARB’s responses thereto.42

Therefore, we find that the Valley State 

SIP Strategy meets the procedural 

requirements for public notice and 

hearing in CAA sections 110(a) and 

110(l) and 40 CFR 51.102. The Valley 

State SIP Strategy became complete by 

operation of law on November 10, 2019. 

C. District Rule 4901 

With respect to the District 

contingency measure, the District states 

in Appendix H of the 2018 PM2.5 Plan 

that it will amend Rule 4901 to include 

a requirement to be triggered upon a 

determination by the EPA that the San 

Joaquin Valley failed to meet a 

regulatory requirement necessitating 

implementation of a contingency 

measure.43 On June 20, 2019, the 

District adopted amendments to Rule 

4901 including a contingency measure 

(in section 5.7.3 of the amended rule), 

and, as an attachment to a letter dated 

July 19, 2019, CARB submitted the 

amended rule to the EPA for approval.44

On July 22, 2020, we approved Rule 

4901, as amended June 20, 2019, into 

the SIP based on our conclusion that the 

rule meets the requirements for 

enforceability and for SIP revisions in 

CAA sections 110(a)(2)(A), 110(l), and 

193 but we did not evaluate section 

5.7.3 of the amended rule for 

compliance with CAA requirements for 

contingency measures.45 As part of that 

rulemaking, we stated that we would 

determine in future actions whether 

section 5.7.3 of Rule 4901, in 

conjunction with other submitted 

provisions, meets the statutory and 

regulatory requirements for contingency 

measures.46 We are now evaluating 

section 5.7.3 of Rule 4901, as amended 

June 20, 2019, for compliance with the 

requirements for contingency measures 

for purposes of the 1997 annual PM2.5

NAAQS. 

Consistent with the requirements of 

40 CFR part 51, Appendix V, we 

previously determined that CARB’s 

submittal of the June 20, 2019 revisions 

to Rule 4901 satisfied the procedural 

requirements for SIP revisions under 

CAA section 110 and the EPA’s 

implementing regulations.47

III. Clean Air Act Requirements for 

Serious PM2.5 Areas That Fail To Attain 

In the event that a Serious area fails 

to attain the PM2.5 NAAQS by the 

applicable attainment date, CAA section 

189(d) requires that ‘‘the State in which 

such area is located shall, after notice 

and opportunity for public comment, 

submit within 12 months after the 

applicable attainment date, plan 

revisions which provide for attainment 

of the . . . standard. . .’’ An attainment 

plan under section 189(d) must, among 

other things, demonstrate expeditious 

attainment of the NAAQS within the 

time period provided under CAA 

section 179(d)(3) and provide for annual 

reductions in emissions of direct PM2.5

or a PM2.5 plan precursor pollutant 

within the area of not less than five 


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48CAA section 189(d) and 40 CFR 51.1010(c). 

49 81 FR 58010, 58098 (August 24, 2016). 

50 Id. Because the EPA has not previously 

approved a SIP submission for the San Joaquin 

Valley as meeting the Serious area planning 

requirements under CAA sections 172 and 189 for 

the 1997 annual PM2.5 NAAQS, the EPA is 

evaluating relevant portions of the SJV PM2.5 Plan 

for compliance with these requirements, in addition 

to the requirements of CAA section 189(d). 

51 81 FR 84481, 84482. 

52 57 FR 13498 (April 16, 1992). 

53 57 FR 18070 (April 28, 1992). 

54 59 FR 41998 (August 16, 1994). 

55 81 FR 58010. 

56 Id. at 58098–58099. 

57 ‘‘Emissions Inventory Guidance for 

Implementation of Ozone and Particulate Matter 

National Ambient Air Quality Standards (NAAQS) 

and Regional Haze Regulations,’’ U.S. EPA, May 

2017 (‘‘Emissions Inventory Guidance’’), available 

at https://www.epa.gov/air-emissions-inventories/ 

air-emissions-inventory-guidance-implementationozone-and-particulate. 

58The Emissions Inventory Guidance identifies 

the types of sources for which the EPA expects 

states to provide condensable PM emissions 

inventories. Emissions Inventory Guidance, section 

4.2.1 (‘‘Condensable PM Emissions’’), 63–65. 

59 40 CFR 51.1008(c)(1). 

60 Id. 

percent per year from the most recent 

emissions inventory for the area until 

attainment.48 In addition to the 

requirement to submit control measures 

providing for a five percent reduction in 

emissions of certain pollutants on an 

annual basis, the EPA interprets CAA 

section 189(d) as requiring a state to 

submit an attainment plan that includes 

the same basic statutory plan elements 

that are required for other attainment 

plans.49 Specifically, a state must 

submit to the EPA its plan to meet the 

requirements of CAA section 189(d) in 

the form of a complete attainment plan 

submission that includes the following 

elements: 

1. A comprehensive, accurate, current 

inventory of actual emissions from all 

sources of PM2.5 and PM2.5 precursors in 

the area; 

2. A control strategy that includes 

additional measures (beyond those 

already adopted in previous SIPs for the 

area as RACM/RACT, best available 

control measures/best available control 

technology (BACM/BACT), and most 

stringent measures (if applicable)) that 

provide for attainment of the standards 

and, from the date of such submission 

until attainment, demonstrate that the 

plan will at a minimum achieve an 

annual five percent reduction in 

emissions of direct PM2.5 or any PM2.5

plan precursor; 

3. A demonstration (including air 

quality modeling) that the plan provides 

for attainment as expeditiously as 

practicable; 

4. Plan provisions that require RFP; 

5. Quantitative milestones that are to 

be achieved every three years until the 

area is redesignated attainment and that 

demonstrate RFP toward attainment by 

the applicable date; 

6. Contingency measures to be 

implemented if the area fails to meet 

any requirement concerning RFP or 

quantitative milestones or to attain by 

the applicable attainment date; and 

7. Provisions to assure that control 

requirements applicable to major 

stationary sources of PM2.5 also apply to 

major stationary sources of PM2.5

precursors, except where the state 

demonstrates to the EPA’s satisfaction 

that such sources do not contribute 

significantly to PM2.5 levels that exceed 

the standards in the area. 

A state with a Serious PM2.5

nonattainment area that fails to attain 

the NAAQS by the applicable Serious 

area attainment date must also address 

any statutory requirements applicable to 

Moderate and Serious nonattainment 

area plans under CAA sections 172 and 

189 of the CAA to the extent that those 

requirements have not already been 

met.50

A section 189(d) plan must 

demonstrate attainment as expeditiously 

as practicable, and no later than five 

years from the date of the EPA’s 

determination that the area failed to 

attain, consistent with sections 179(d)(3) 

and 172(a)(2) of the CAA.51 Pursuant to 

those provisions, the Administrator may 

also extend the attainment date to the 

extent the Administrator deems 

appropriate, for a period no greater than 

10 years from the effective date of the 

EPA’s determination that the area failed 

to attain, considering the severity of 

nonattainment and the availability and 

feasibility of pollution control measures. 

The EPA provided its preliminary 

views on the CAA’s requirements for 

particulate matter plans under part D, 

title I of the Act in the following 

guidance documents: (1) ‘‘State 

Implementation Plans; General 

Preamble for the Implementation of 

Title I of the Clean Air Act Amendments 

of 1990’’ (‘‘General Preamble’’); 52 (2) 

‘‘State Implementation Plans; General 

Preamble for the Implementation of 

Title I of the Clean Air Act Amendments 

of 1990; Supplemental’’ (‘‘General 

Preamble Supplement’’); 53 and (3) 

‘‘State Implementation Plans for Serious 

PM–10 Nonattainment Areas, and 

Attainment Date Waivers for PM–10 

Nonattainment Areas Generally; 

Addendum to the General Preamble for 

the Implementation of Title I of the 

Clean Air Act Amendments of 1990’’ 

(‘‘General Preamble Addendum’’).54

More recently, in an August 24, 2016 

final rule entitled, ‘‘Fine Particulate 

Matter National Ambient Air Quality 

Standards: State Implementation Plan 

Requirements’’ (‘‘PM2.5 SIP 

Requirements Rule’’), the EPA 

established regulatory requirements and 

provided further interpretive guidance 

on the statutory SIP requirements that 

apply to areas designated nonattainment 

for the PM2.5 standards.55 We discuss 

these regulatory requirements and 

interpretations of the Act as appropriate 

in our evaluation of the SJV PM2.5 Plan 

that follows. 

IV. Review of the San Joaquin Valley 

PM2.5 Plan 

A. Emissions Inventories 

1. Statutory and Regulatory 

Requirements 

CAA section 172(c)(3) requires that 

each SIP include a comprehensive, 

accurate, current inventory of actual 

emissions from all sources of the 

relevant pollutant or pollutants in the 

nonattainment area. The EPA discussed 

the emissions inventory requirements 

that apply to PM2.5 nonattainment areas 

in the PM2.5 SIP Requirements Rule and 

codified these requirements in 40 CFR 

51.1008.56 The EPA has also issued 

guidance concerning emissions 

inventories for PM2.5 nonattainment 

areas.57

The base year emissions inventory 

should provide a state’s best estimate of 

actual emissions from all sources of the 

relevant pollutants in the area, i.e., all 

emissions that contribute to the 

formation of a particular NAAQS 

pollutant. For the PM2.5 NAAQS, the 

base year inventory must include direct 

PM2.5 emissions, separately reported 

filterable and condensable PM2.5

emissions,58 and emissions of all 

chemical precursors to the formation of 

secondary PM2.5: nitrogen oxides (NOX), 

sulfur dioxide (SO2), volatile organic 

compounds (VOC), and ammonia.59 In 

addition, the emissions inventory base 

year for a Serious PM2.5 nonattainment 

area subject to CAA section 189(d) must 

be one of the three years for which 

monitored data were used to determine 

that the area failed to attain the PM2.5

NAAQS by the applicable Serious area 

attainment date, or another technically 

appropriate year justified by the state in 

its Serious area SIP submission.60 A 

state’s SIP submission must include 

documentation explaining how it 

calculated emissions data for the 

inventory. In estimating mobile source 

emissions, a state should use the latest 

emissions models and planning 

assumptions available at the time the 

SIP is developed. The latest EPAapproved version of California’s mobile 


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61 80 FR 77337 (December 14, 2015). EMFAC is 

short for EMission FACtor. The EPA announced the 

availability of the EMFAC2014 model, effective on 

the date of publication in the Federal Register, for 

use in state implementation plan development and 

transportation conformity in California. Upon that 

action, EMFAC2014 was required to be used for all 

new regional emissions analyses and CO, PM10, and 

PM2.5 hot-spot analyses that were started on or after 

December 14, 2017, which was the end of the grace 

period for using the prior mobile source emissions 

model, EMFAC2011. 

62 84 FR 41717 (August 15, 2019). The grace 

period for new regional emissions analyses begins 

on August 15, 2019 and ends on August 16, 2021, 

while the grace period for hot-spot analyses begins 

on August 15, 2019 and ends on August 17, 2020. 

84 FR 41717, 41720. 

63The EPA released an update to AP–42 in 

January 2011 that revised the equation for 

estimating paved road dust emissions based on an 

updated data regression that included new emission 

tests results. 76 FR 6328 (February 4, 2011). CARB 

used the revised 2011 AP–42 methodology in 

developing on-road mobile source emissions; see 

http://www.arb.ca.gov/ei/areasrc/fullpdf/full7-9_

2016.pdf. 

64AP–42 has been published since 1972 as the 

primary source of the EPA’s emission factor 

information and is available at https://

www.epa.gov/air-emissions-factors-andquantification/ap-42-compilation-air-emissionsfactors. It contains emission factors and process 

information for more than 200 air pollution source 

categories. A source category is a specific industry 

sector or group of similar emitting sources. The 

emission factors have been developed and compiled 

from source test data, material balance studies, and 

engineering estimates. 

65 40 CFR 51.1008 and 51.1012. See also 

Emissions Inventory Guidance, section 3 (‘‘SIP 

Inventory Requirements and Recommendations’’). 

66 40 CFR 51.1004, 51.1008, 51.1011, and 

51.1012. 

67 40 CFR 51.165(a)(3)(ii)(C)(1). 

68The SJV PM2.5 Plan generally uses ‘‘sulfur 

oxides’’ or ‘‘SOX’’ in reference to SO2 as a precursor 

to the formation of PM2.5. We use SOX and SO2

interchangeably throughout this notice. 

69The SJV PM2.5 Plan generally uses ‘‘reactive 

organic gasses’’ or ‘‘ROG’’ in reference to VOC as 

a precursor to the formation of PM2.5. We use ROG 

and VOC interchangeably throughout this notice. 

70The EPA regulations refer to ‘‘non-road’’ 

vehicles and engines whereas CARB regulations 

refer to ‘‘Other Mobile Sources’’ or ‘‘off-road’’ 

vehicles and engines. These terms refer to the same 

types of vehicles and engines. We refer herein to 

such vehicles and engines as ‘‘non-road’’ sources. 

71 2018 PM2.5 Plan, Appendix B, B–18 to B–19. 

The winter average daily planning inventory 

corresponds to the months of November through 

April when daily ambient PM2.5 concentrations are 

typically highest. The base year inventory is from 

the California Emissions Inventory Development 

and Reporting System (CEIDARS) and future year 

inventories were estimated using the California 

Emission Projection Analysis Model (CEPAM), 2016 

SIP Baseline Emission Projections, version 1.05. 

72 2018 PM2.5 Plan, Appendix B, section B.2 

(‘‘Emissions Inventory Summary and 

Methodology’’). 

73 Id. at B–42 to B–44. 

74 Id. at B–37. 

75 Id. at B–28. 

76 Id. at B–18 and B–19. 

source emission factor model for 

estimating tailpipe, brake, and tire wear 

emissions from on-road mobile sources 

that was available during the State’s and 

District’s development of the SJV PM2.5

Plan was EMFAC2014.61 Following 

CARB’s submission of the Plan, the EPA 

approved EMFAC2017, the latest 

revision to this mobile source emissions 

model, and established grace periods 

during which EMFAC2014 may 

continue to be used for transportation 

conformity purposes (i.e., new regional 

emissions analyses and CO, PM10, and 

PM2.5 hot-spot analyses).62 States are 

also required to use the EPA’s 

‘‘Compilation of Air Pollutant Emission 

Factors’’ (‘‘AP–42’’) road dust method 

for calculating re-entrained road dust 

emissions from paved roads.63 64

In addition to the base year inventory 

submitted to meet the requirements of 

CAA section 172(c)(3), the state must 

also submit a projected attainment year 

inventory and emissions projections for 

each RFP milestone year.65 These future 

emissions projections are necessary 

components of the attainment 

demonstration required under CAA 

section 189(d) and the demonstration of 

RFP required under section 172(c)(2).66

Emissions projections for future years 

(referred to in the Plan as ‘‘forecasted 

inventories’’) should account for, among 

other things, the ongoing effects of 

economic growth and adopted 

emissions control requirements. The 

state’s SIP submission should include 

documentation to explain how the 

emissions projections were calculated. 

Where a state chooses to allow new 

major stationary sources or major 

modifications to use emission reduction 

credits (ERCs) that were generated 

through shutdown or curtailed 

emissions units occuring before the base 

year of an attainment plan, the projected 

emissions inventory used to develop the 

attainment demonstration must 

explicitly include the emissions from 

such previously shutdown or curtailed 

emissions units.67

2. Summary of the State’s Submission 

Summaries of the planning emissions 

inventories for direct PM2.5 and PM2.5

precursors (NOX, SOX,68 VOC,69 and 

ammonia) and the documentation for 

the inventories for the San Joaquin 

Valley PM2.5 nonattainment area are 

included in Appendix B (‘‘Emissions 

Inventory’’) and Appendix I (‘‘New 

Source Review and Emission Reduction 

Credits’’) of the 2018 PM2.5 Plan. 

CARB and District staff worked 

together to develop the emissions 

inventories for the San Joaquin Valley 

PM2.5 nonattainment area. The District 

worked with operators of the stationary 

facilities in the nonattainment area to 

develop the stationary source emissions 

estimates. The responsibility for 

developing emissions estimates for area 

sources such as agricultural burning and 

paved road dust was shared by the 

District and CARB. CARB staff 

developed the emissions inventories for 

both on-road and non-road mobile 

sources.70

The Plan includes winter (24-hour) 

average and annual average daily 

planning inventories for the 2013 base 

year, which were modeled from the 

2012 emissions inventory, and 

estimated emissions for forecasted years 

from 2017 through 2028 for the 

attainment and RFP demonstrations for 

the 1997, 2006, and 2012 PM2.5

NAAQS.71 In this proposal, we are 

proposing action on those winter 

average and annual average emissions 

inventories necessary to support the 

attainment plan for the 1997 annual 

PM2.5 NAAQS—i.e., the 2013 base year 

inventory, forecasted inventories for the 

RFP milestone years of 2017, 2020 

(attainment year), and 2023 (postattainment milestone year), and 

additional forecasted inventories for 

2018 and 2019 to support the five 

percent annual emission reduction 

demonstration. Each inventory includes 

emissions from stationary, area, on-road, 

and non-road sources. 

The base year inventories for 

stationary sources were developed using 

actual emissions reports from facility 

operators. The State developed the base 

year emissions inventory for area 

sources using the most recent models 

and methodologies available at the time 

the State was developing the Plan.72 The 

Plan also includes background, 

methodology, and inventories of 

condensable and filterable PM2.5

emissions from stationary point and 

non-point combustion sources that are 

expected to generate condensable 

PM2.5.73 CARB used EMFAC2014 to 

estimate on-road motor vehicle 

emissions based on transportation 

activity data from the 2014 Regional 

Transportation Plan (2014 RTP) adopted 

by the transportation planning agencies 

in the San Joaquin Valley.74 Reentrained paved road dust emissions 

were calculated using a CARB 

methodology consistent with the EPA’s 

AP–42 road dust methodology.75

CARB developed the emissions 

forecasts by applying growth and 

control profiles to the base year 

inventory. CARB’s mobile source 

emissions projections take into account 

predicted activity rates and vehicle fleet 

turnover by vehicle model year and 

adopted controls.76 In addition, the Plan 

states that the District is providing for 

use of pre-base year ERCs as offsets by 

accounting for such ERCs in the 


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77 2018 PM2.5 Plan, Appendix I, I–1 to I–5. 

78 Id. at tables I–1 to I–5. 

79 81 FR 84481, 84482 (November 23, 2016). 

80 ‘‘Air Quality Criteria for Particulate Matter’’ 

(EPA/600/P–99/002aF), EPA, October 2004, Chapter 

3. 81 ‘‘Regulatory Impact Analysis for the Final 

Revisions to the National Ambient Air Quality 

Standards for Particulate Matter’’ (EPA/452/R–12– 

005), EPA, December 2012), 2–1. 

82 81 FR 58010, 58017–58020. 

projected 2025 emissions inventory.77

The 2018 PM2.5 Plan identifies growth 

factors, control factors, and estimated 

offset use between 2013 and 2025 for 

direct PM2.5, NOX, SOX, and VOC 

emissions by source category and lists 

all pre-base year ERCs issued by the 

District for PM10, NOX, SOX, and VOC 

emissions, by facility.78

Table 1 provides a summary of the 

winter (24-hour) average inventories in 

tons per day (tpd) of direct PM2.5 and 

PM2.5 precursors for the 2013 base year. 

Table 2 provides a summary of annual 

average inventories of direct PM2.5 and 

PM2.5 precursors for the 2013 base year. 

These annual average inventories 

provide the basis for the control 

measure analysis and the RFP and 

attainment demonstrations in the SJV 

PM2.5 Plan. 

TABLE 1—SAN JOAQUIN VALLEY WINTER AVERAGE EMISSIONS INVENTORY FOR DIRECT PM2.5 AND PM2.5 PRECURSORS

FOR THE 2013 BASE YEAR

[tpd] 

Category Direct PM2.5 NOX SOX VOC Ammonia 

Stationary Sources .................................................................................. 8.5 35.0 6.9 86.6 13.9 

Area Sources ........................................................................................... 41.4 11.5 0.5 156.8 291.5 

On-Road Mobile Sources ........................................................................ 6.4 188.7 0.6 51.1 4.4 

Non-Road Mobile Sources ....................................................................... 4.4 65.3 0.3 27.4 0.0 

Totals a .............................................................................................. 60.8 300.5 8.4 321.9 309.8 

Source: 2018 PM2.5 Plan, Appendix B, tables B–1 to B–5. aTotals reflect disaggregated emissions and may not add exactly as shown here due to rounding. 

TABLE 2—SAN JOAQUIN VALLEY ANNUAL AVERAGE EMISSIONS INVENTORY FOR DIRECT PM2.5 AND PM2.5 PRECURSORS

FOR THE 2013 BASE YEAR

[tpd] 

Category Direct PM2.5 NOX SOX VOC Ammonia 

Stationary Sources .................................................................................. 8.8 38.6 7.2 87.1 13.9 

Area Sources ........................................................................................... 41.5 8.1 0.3 153.4 310.9

On-Road Mobile Sources ........................................................................ 6.4 183.1 0.6 49.8 4.4 

Non-Road Mobile Sources ....................................................................... 5.8 87.4 0.3 33.8 0.0 

Totals a .............................................................................................. 62.5 317.2 8.5 324.1 329.2 

Source: 2018 PM2.5 Plan, Appendix B, tables B–1 to B–5. aTotals reflect disaggregated emissions and may not add exactly as shown here due to rounding. 

3. The EPA’s Evaluation and Proposed 

Action 

We have reviewed the 2013 base year 

emissions inventories in the SJV PM2.5

Plan and emissions inventory 

estimation methodologies used by 

California for consistency with CAA 

requirements and the EPA’s guidance. 

We find that the inventories are based 

on the most current and accurate 

information available to the State and 

District at the time they were 

developing the Plan and inventories, 

including the latest version of 

California’s mobile source emissions 

model that had been approved by the 

EPA at the time, EMFAC2014. The 

inventories comprehensively address all 

source categories in the San Joaquin 

Valley PM2.5 nonattainment area and are 

consistent with the EPA’s inventory 

guidance. 

In accordance with 40 CFR 

51.1008(c)(1), the 2013 base year is one 

of the three years for which monitored 

data were used to determine that the 

San Joaquin Valley area failed to attain 

the PM2.5 NAAQS by the applicable 

Serious area attainment date for the 

1997 annual PM2.5 NAAQS,79 and it 

represents actual annual average 

emissions of all sources within the 

nonattainment area. Direct PM2.5 and 

PM2.5 precursors are included in the 

inventories, and filterable and 

condensable direct PM2.5 emissions are 

identified separately. 

For these reasons, we are proposing to 

approve the 2013 base year emissions 

inventories in the SJV PM2.5 Plan for the 

1997 annual PM2.5 NAAQS as meeting 

the requirements of CAA section 

172(c)(3) and 40 CFR 51.1008. 

B. PM2.5 Precursors 

1. Statutory and Regulatory 

Requirements 

The composition of PM2.5 is complex 

and highly variable due in part to the 

large contribution of secondary PM2.5 to 

total fine particle mass in most 

locations, and to the complexity of 

secondary particle formation processes. 

A large number of possible chemical 

reactions, often non-linear in nature, 

can convert gaseous NOX, SO2, VOC, 

and ammonia to PM2.5, making them 

precursors to PM2.5.80 Formation of 

secondary PM2.5 may also depend on 

atmospheric conditions, including solar 

radiation, temperature, and relative 

humidity, and the interactions of 

precursors with preexisting particles 

and with cloud or fog droplets.81

Under subpart 4 of part D, title I of the 

CAA and the PM2.5 SIP Requirements 

Rule, each state containing a PM2.5

nonattainment area must evaluate all 

PM2.5 precursors for regulation unless, 

for any given PM2.5 precursor, the state 

demonstrates to the Administrator’s 

satisfaction that such precursor does not 

contribute significantly to PM2.5 levels 

that exceed the NAAQS in the 

nonattainment area.82 The provisions of 


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83CAA section 302(g). 

84 81 FR 58010, 58015. 

85 Id. at 58018–58019. 

86 General Preamble, 57 FR 13498, 13539–13542. 

87Courts have upheld this approach to the 

requirements of subpart 4 for PM10. See, e.g., Assoc. 

of Irritated Residents v. EPA, et al., 423 F.3d 989 

(9th Cir. 2005). 

88 40 CFR 51.1006(a)(1). 

89 Id. 

90 ‘‘PM2.5 Precursor Demonstration Guidance,’’ 

EPA–454/R–19–004, May 2019, including 

memorandum dated May 30, 2019 from Scott 

Mathias, Acting Director, Air Quality Policy 

Division and Richard Wayland, Director, Air 

Quality Assessment Division, Office of Air Quality 

Planning and Standards (OAQPS), EPA to Regional 

Air Division Directors, Regions 1–10, EPA. 

91 ‘‘PM2.5 Precursor Demonstration Guidance, 

Draft for Public Review and Comments,’’ EPA–454/ 

P–16–001, November 17, 2016, including 

memorandum dated November 17, 2016 from 

Stephen D. Page, Director, OAQPS, EPA to Regional 

Air Division Directors, Regions 1–10, EPA. 

92A copy of the contents of Appendix G appears 

in the CARB Staff Report, Appendix C4 (‘‘Precursor 

Demonstrations for Ammonia, SOX, and ROG’’). 

93Letter dated May 9, 2019, from Richard Corey, 

Executive Officer, CARB, to Michael Stoker, 

Regional Administrator, EPA Region 9, Attachment 

A (‘‘Clarifying information for the San Joaquin 

Valley 2018 Plan regarding model sensitivity 

related to ammonia and ammonia controls’’). 

94Email dated June 20, 2019, from Jeremy Avise, 

CARB, to Scott Bohning, EPA Region IX, Subject: 

‘‘RE: SJV model disbenefit from SOX reduction,’’ 

with attachment (‘‘CARB’s June 2019 Precursor 

Clarification’’); email dated September 19, 2019, 

from Jeremy Avise, CARB, to Scott Bohning, EPA 

Region IX, Subject: ‘‘FW: SJV species responses,’’ 

with attachments (‘‘CARB’s September 2019 

Precursor Clarification’’); email dated October 18, 

2019, from Laura Carr, CARB, to Scott Bohning, 

Jeanhee Hong, and Rory Mays, EPA Region IX, 

Subject: ‘‘Clarifying information on ammonia,’’ with 

attachment ‘‘Clarifying Information on Ammonia’’ 

(‘‘CARB’s October 2019 Precursor Clarification’’); 

email dated April 19, 2021, from Laura Carr, CARB, 

to Rory Mays, EPA Region IX, Subject: ‘‘Ammonia 

update,’’ with attachment ‘‘Update on Ammonia in 

the San Joaquin Valley’’ (‘‘CARB’s April 19, 2021 

Precursor Clarification’’); and email dated April 26, 

2021, from Laura Carr, CARB, to Scott Bohning, 

EPA Region IX, Subject: ‘‘RE: Ammonia update,’’ 

with attachment ‘‘Ammonia in San Joaquin Valley’’ 

(‘‘CARB’s April 26, 2021 Precursor Clarification’’). 

95CARB Staff Report, Appendix C, 9–16. The 

CARB Staff Report, Appendix C4 (‘‘Precursor 

Demonstrations for Ammonia, SOX, and ROG’’) is 

very similar to the contents of Appendix G of the 

2018 PM2.5 Plan. 

subpart 4 do not define the term 

‘‘precursor’’ for purposes of PM2.5, nor 

do they explicitly require the control of 

any specifically identified PM2.5

precursor. The statutory definition of 

‘‘air pollutant,’’ however, provides that 

the term ‘‘includes any precursors to the 

formation of any air pollutant, to the 

extent the Administrator has identified 

such precursor or precursors for the 

particular purpose for which the term 

‘air pollutant’ is used.’’ 83 The EPA has 

identified NOX, SO2, VOC, and 

ammonia as precursors to the formation 

of PM2.5.84 Accordingly, the attainment 

plan requirements of subpart 4 apply to 

emissions of all four precursor 

pollutants and direct PM2.5 from all 

types of stationary, area, and mobile 

sources, except as otherwise provided in 

the Act (e.g., CAA section 189(e)). 

Section 189(e) of the Act requires that 

the control requirements for major 

stationary sources of direct PM10 also 

apply to major stationary sources of 

PM10 precursors, except where the 

Administrator determines that such 

sources do not contribute significantly 

to PM10 levels that exceed the standard 

in the area. Section 189(e) contains the 

only express exception to the control 

requirements under subpart 4 (e.g., 

requirements for RACM and RACT, 

BACM and BACT, most stringent 

measures, and new source review 

(NSR)) for sources of direct PM2.5 and 

PM2.5 precursor emissions. Although 

section 189(e) explicitly addresses only 

major stationary sources, the EPA 

interprets the Act as authorizing it also 

to determine, under appropriate 

circumstances, that regulation of 

specific PM2.5 precursors from other 

source categories in a given 

nonattainment area is not necessary.85

For example, under the EPA’s 

longstanding interpretation of the 

control requirements that apply to 

stationary, area, and mobile sources of 

PM10 precursors in the nonattainment 

area under CAA section 172(c)(1) and 

subpart 4,86 a state may demonstrate in 

a SIP submission that control of a 

certain precursor pollutant is not 

necessary in light of its insignificant 

contribution to ambient PM10 levels in 

the nonattainment area.87

Under the PM2.5 SIP Requirements 

Rule, a state may elect to submit to the 

EPA a ‘‘comprehensive precursor 

demonstration’’ for a specific 

nonattainment area to show that 

emissions of a particular precursor from 

all existing sources located in the 

nonattainment area do not contribute 

significantly to PM2.5 levels that exceed 

the standards in the area.88 If the EPA 

determines that the contribution of the 

precursor to PM2.5 levels in the area is 

not significant and approves the 

demonstration, the state is not required 

to control emissions of the relevant 

precursor from existing sources in the 

attainment plan.89

In addition, in May 2019, the EPA 

issued the ‘‘Fine Particulate Matter 

(PM2.5) Precursor Demonstration 

Guidance’’ (‘‘PM2.5 Precursor 

Guidance’’),90 which provides 

recommendations to states for analyzing 

nonattainment area PM2.5 emissions and 

developing such optional precursor 

demonstrations, consistent with the 

PM2.5 SIP Requirements Rule. The PM2.5

Precursor Guidance builds upon the 

draft version of the guidance, released 

on November 17, 2016 (‘‘Draft PM2.5

Precursor Guidance’’), which CARB 

referenced in developing its precursor 

demonstration in the SJV PM2.5 Plan.91

The EPA’s recommendations in the 

PM2.5 Precursor Guidance are 

essentially the same as those in the Draft 

PM2.5 Precursor Guidance, including the 

recommended annual contribution 

threshold of 0.2 mg/m3. 

We are evaluating the SJV PM2.5 Plan 

in accordance with the presumption 

embodied within subpart 4 that all 

PM2.5 precursors must be addressed in 

the State’s evaluation of potential 

control measures, unless the State 

adequately demonstrates that emissions 

of a particular precursor or precursors 

do not contribute significantly to 

ambient PM2.5 levels that exceed the 

PM2.5 NAAQS in the nonattainment 

area. In reviewing any determination by 

the State to exclude a PM2.5 precursor 

from the required evaluation of 

potential control measures, we consider 

both the magnitude of the precursor’s 

contribution to ambient PM2.5

concentrations in the nonattainment 

area and the sensitivity of ambient PM2.5

concentrations in the area to reductions 

in emissions of that precursor. 

2. Summary of the State’s Submission 

The State presents a summary of its 

PM2.5 precursor analysis in Chapter 5 of 

the 2018 PM2.5 Plan and the full 

precursor demonstration in Appendix G 

(‘‘Precursor Demonstration’’) of the 2018 

PM2.5 Plan.92 Additional modeling 

results are presented in Appendix K 

(‘‘Modeling Attainment 

Demonstration’’), section 5.6 (‘‘PM2.5

Precursor Sensitivity Analysis’’). CARB 

also provided clarifying information on 

its precursor assessment, including an 

Attachment A to its letter transmitting 

the 2018 PM2.5 Plan to the EPA 93 and 

further clarifications in five email 

transmittals.94 The CARB Staff Report 

contains additional discussion of the 

role of ammonia in the formation of 

ammonium nitrate and the role of VOC 

in the formation of ammonium nitrate 

and secondary organic aerosol.95

The Plan provides both concentrationbased and sensitivity-based analyses of 

precursor contributions to ambient 

PM2.5 concentrations in the San Joaquin 

Valley. The State supplemented the 

sensitivity analysis, particularly for 

ammonia, with additional information, 

including factors identified in the PM2.5

Precursor Guidance, such as emission 

trends, the appropriateness of future 

year versus base year sensitivity, 

available emission controls, and the 


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96PM2.5 Precursor Guidance, 18–19 

(consideration of additional information), 31 

(available emission controls), and 35–36 

(appropriateness of future year versus base year 

sensitivity). 

97 Direct PM2.5 emissions are considered a 

primary source of ambient PM2.5 (i.e., no further 

formation in the atmosphere is required), and 

therefore is not considered a precursor pollutant 

under subpart 4, which may differ from a more 

generalized understanding of what contributes to 

ambient PM2.5. 

98 2018 PM2.5 Plan, Appendix G, 3. The Plan does 

not present a concentration-based analysis for the 

24-hour average concentrations in the San Joaquin 

Valley. Instead, CARB relied on the annual average 

concentration-based analysis as an interim step to 

the sensitivity-based analysis, for which CARB 

assessed the sensitivity of both 24-hour average and 

annual average ambient PM2.5 concentrations to 

precursor emissions reductions. Separately, the 

Plan presents a graphical representation of annual 

average ambient PM2.5 components (i.e., crustal 

particulate matter, elemental carbon, organic 

matter, ammonium sulfate, and ammonium nitrate) 

for 2011–2013 for Bakersfield, Fresno, and Modesto. 

2018 PM2.5 Plan, Chapter 3, 3–3 to 3–4. 

99This procedure is the procedure recommended 

by the EPA. PM2.5 Precursor Guidance, 37. 

100 81 FR 58010, 58100. 

101 40 CFR 50.1010(c)(2)(ii). 

102CAA section 189(d) and 40 CFR 51.1010(c). 

103 81 FR 58010, 58101. The new projected 

attainment date is established by the EPA in 

accordance with the provisions of CAA sections 

179(d)(3) and 172(a)(2), which require that the new 

attainment date be as expeditious as practicable but 

no later than 5 years from the date of publication 

in the Federal Register of the EPA’s determination 

that the area failed to attain the relevant NAAQS, 

except that the EPA may extend the attainment date 

by up to 5 additional years based on the severity 

of nonattainment and the availability and feasibility 

of pollution control measures. Id. at 58103. 

severity of nonattainment.96 These 

analyses led the State to conclude that 

direct PM2.5 and NOX emissions 

contribute significantly to ambient 

PM2.5 levels that exceed the PM2.5

NAAQS in the San Joaquin Valley while 

ammonia, SOX, and VOC do not 

contribute significantly to such 

exceedances.97 We summarize the 

State’s analysis and conclusions below. 

For a more detailed summary of the 

precursor demonstration in the Plan, 

please refer to the EPA’s ‘‘Technical 

Support Document, EPA Evaluation of 

PM2.5 Precursor Demonstration, San 

Joaquin Valley PM2.5 Plan for the 2006 

PM2.5 NAAQS,’’ February 2020 (‘‘EPA’s 

PM2.5 Precursor TSD’’). 

For ammonia, SOX, and VOC, CARB 

assessed the 2015 annual average 

concentration of each precursor in 

ambient PM2.5 at Bakersfield, for which 

the necessary speciated PM2.5 data are 

available and where the highest PM2.5

design values have been recorded in 

most years, and compared those 

concentrations to the recommended 

annual average contribution threshold 

of 0.2 mg/m3 from the Draft PM2.5

Precursor Guidance, which was 

available at the time the State developed 

the SIP.98 The contributions of 

ammonia, SOX, and VOC were 5.2 mg/ 

m3, 1.6 mg/m3, and 6.2 mg/m3, 

respectively. Given that these levels are 

well above the EPA’s 0.2 mg/m3

recommended contribution threshold, 

the State proceeded with a sensitivitybased analysis. 

The State’s sensitivity-based analysis 

used the same Community Multiscale 

Air Quality (CMAQ) modeling platform 

as that used for the Plan’s attainment 

demonstration. The State modeled the 

sensitivity of ambient PM2.5

concentration in the San Joaquin Valley 

to 30 percent and 70 percent emissions 

reductions in 2013, 2020, and 2024 for 

each of ammonia, SOX, and VOC. The 

State estimated baseline (2013, 2020, 

and 2024) design values for PM2.5 using 

relative response factors (RRFs) and 

calculated the ammonia, SOX, and VOC 

precursor contribution for a given year 

and for each sensitivity scenario (30 

percent and 70 percent emissions 

reductions) as the difference between its 

baseline design value and the design 

value for each sensitivity scenario.99

Based on these analyses and supporting 

information, the State concludes that 

ammonia, SOX, and VOC emissions do 

not contribute significantly to PM2.5

levels that exceed the 1997 annual PM2.5

NAAQS in the San Joaquin Valley. 

3. The EPA’s Evaluation and Proposed 

Action 

As discussed in section IV of this 

proposal, the EPA is proposing to 

disapprove the attainment 

demonstration and related elements in 

the SJV PM2.5 Plan for the 1997 annual 

PM2.5 NAAQS, including the five 

percent annual emission reductions 

demonstration, reasonable further 

progress (RFP) demonstration, and 

quantitative milestones, based on 

ambient monitoring data that show that 

the Plan was insufficient to achieve 

attainment of the 1997 annual PM2.5

NAAQS by December 31, 2020, the 

State’s projected attainment date. Given 

that we are proposing to disapprove the 

attainment demonstration, and given 

that the precursor demonstration for the 

1997 annual PM2.5 NAAQS largely relies 

on the technical analyses and 

assumptions that provide the basis for 

the attainment demonstration, we are 

also proposing to disapprove the 

precursor demonstration in the SJV 

PM2.5 Plan for the 1997 annual PM2.5

NAAQS. Therefore, all precursors to the 

formation of PM2.5 in the San Joaquin 

Valley (i.e., NOX, ammonia, SOX, and 

VOC) remain ‘‘PM2.5 plan precursors’’ as 

defined in 40 CFR 51.1000 for purposes 

of the 1997 annual PM2.5 NAAQS for the 

Plan that is the subject of this proposal. 

If the EPA takes final action on the 

SJV PM2.5 Plan as proposed, California 

will be required to develop and submit 

a revised plan for the San Joaquin 

Valley area that addresses the applicable 

CAA requirements, including the 

requirements of CAA section 189(d). 

Under 40 CFR 51.1006, the State will be 

required to submit an updated precursor 

demonstration if it seeks to exempt 

sources of a particular precursor from 

control requirements in the new Serious 

area attainment demonstration. For 

these reasons, and because we are 

proposing to disapprove the precursor 

demonstration on the basis of our 

proposed disapproval of the attainment 

demonstration, we are not providing a 

full evaluation of the precursor 

demonstration for the 1997 annual PM2.5

NAAQS in the SJV PM2.5 Plan at this 

time. 

C. Attainment Plan Control Strategy 

1. Statutory and Regulatory 

Requirements 

The overarching requirement for the 

CAA section 189(d) attainment control 

strategy is that it provides for attainment 

of the standards as expeditiously as 

practicable.100 The control strategy must 

include any additional measures 

(beyond those already adopted in 

previous SIPs for the area as RACM/ 

RACT or BACM/BACT) that are needed 

for the area to attain expeditiously. This 

includes reassessing any measures 

previously rejected during the 

development of any Moderate area or 

Serious area attainment plan control 

strategy.101 The plan must also 

demonstrate that it will, at a minimum, 

achieve an annual five percent 

reduction in emissions of direct PM2.5 or 

any PM2.5 plan precursor from sources 

in the area until attainment, based on 

the most recent emissions inventory for 

the area.102

In the PM2.5 SIP Requirements Rule, 

the EPA clarified its interpretation of 

the statutory language in CAA section 

189(d) requiring a state to submit a new 

attainment plan to achieve annual 

reductions ‘‘from the date of such 

submission until attainment,’’ to mean 

annual reductions beginning from the 

due date of such submission until the 

new projected attainment date for the 

area based on the new or additional 

control measures identified to achieve at 

least five percent emissions reductions 

annually.103 This interpretation is 

intended to make clear that even if a 

state is late in submitting its CAA 

section 189(d) plan, the area must still 

achieve its annual five percent emission 

reductions beginning from the date by 


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104 40 CFR 51.1000 (definitions). In longstanding 

guidance, the EPA has similarly defined BACM to 

mean, ‘‘among other things, the maximum degree of 

emissions reduction achievable for a source or 

source category, which is determined on a case-bycase basis considering energy, environmental, and 

economic impacts.’’ General Preamble Addendum, 

42010, 42013. 105 81 FR 58010, 58081 and General Preamble 

Addendum, 42011, 42013. 

106 Id. and General Preamble Addendum, 42009– 

42010. 

107 81 FR 58010, 58083–58085. 

108 40 CFR 51.1010(a)(3) and 81 FR 58010, 58041– 

58042. 

109 2018 PM2.5 Plan, Chapter 4, Table 4–2. 

110 2018 PM2.5 Plan, Chapter 4, 4–9. For CARB’s 

BACM analysis for mobile source measures, see 

2018 PM2.5 Plan, Appendix D, including analyses 

for on-road light-duty vehicles and fuels (starting on 

page D–17), on-road heavy-duty vehicles and fuels 

(starting on page D–35), and non-road sources 

(starting on page D–64). 

111For example, see 81 FR 39424 (June 16, 2016); 

82 FR 14446 (March 21, 2017); and 83 FR 23232 

(May 18, 2018). 

which the state was required to make its 

CAA section 189(d) submission, not by 

some later date. Because the deadline 

for California to submit a section 189(d) 

plan for the 1997 PM2.5 NAAQS in the 

San Joaquin Valley was December 31, 

2016, one year after the December 31, 

2015 attainment date for these NAAQS 

under CAA section 188(c)(2), the 

starting point for the five percent 

emission reduction requirement under 

section 189(d) for this area is 2017. 

As discussed in section III of this 

proposed rule, a state with a Serious 

PM2.5 nonattainment area that fails to 

attain the NAAQS by the applicable 

Serious area attainment date must also 

address any statutory requirements 

applicable to Moderate and Serious 

nonattainment area plans under CAA 

sections 172 and 189 of the CAA to the 

extent that those requirements have not 

already been met. Because the EPA has 

not previously taken action to approve 

the California SIP as meeting the 

Serious nonattainment area planning 

requirements under CAA sections 172 

and 189 for the 1997 annual PM2.5

NAAQS for the San Joaquin Valley area, 

the EPA is reviewing the SJV PM2.5 Plan 

for compliance with those requirements, 

including the requirement for BACM. 

Section 189(b)(1)(B) of the Act 

requires for any Serious PM2.5

nonattainment area that the state submit 

provisions to assure that BACM for the 

control of PM2.5 and PM2.5 precursors 

shall be implemented no later than four 

years after the date the area is 

reclassified as a Serious area. The EPA 

has defined BACM in the PM2.5 SIP 

Requirements Rule to mean ‘‘any 

technologically and economically 

feasible control measure that . . . can 

achieve greater permanent and 

enforceable emissions reductions of 

direct PM2.5 emissions and/or emissions 

of PM2.5 plan precursors from sources in 

the area than can be achieved through 

the implementation of RACM on the 

same source(s). BACM includes best 

available control technology 

(BACT).’’ 104

The EPA generally considers BACM a 

control level that goes beyond existing 

RACM-level controls, for example by 

expanding the use of RACM controls or 

by requiring preventative measures 

instead of remediation.105 Indeed, as 

implementation of BACM and BACT is 

required when a Moderate 

nonattainment area is reclassified as 

Serious due to its inability to attain the 

NAAQS through implementation of 

‘‘reasonable’’ measures, it is logical that 

‘‘best’’ control measures should 

represent a more stringent and 

potentially more costly level of 

control.106 If RACM and RACT level 

controls of emissions have been 

insufficient to reach attainment, the 

CAA contemplates the implementation 

of more stringent controls, controls on 

more sources, or other adjustments to 

the control strategy necessary to attain 

the NAAQS in the area. 

Consistent with longstanding 

guidance provided in the General 

Preamble Addendum, the preamble to 

the PM2.5 SIP Requirements Rule 

discusses the following steps for 

determining BACM and BACT: 

(1) Develop a comprehensive 

emissions inventory of the sources of 

PM2.5 and PM2.5 precursors; 

(2) Identify potential control 

measures; 

(3) Determine whether an available 

control measure or technology is 

technologically feasible; 

(4) Determine whether an available 

control measure or technology is 

economically feasible; and 

(5) Determine the earliest date by 

which a control measure or technology 

can be implemented in whole or in 

part.107

The EPA allows consideration of 

factors such as physical plant layout, 

energy requirements, needed 

infrastructure, and workforce type and 

habits when considering technological 

feasibility. For purposes of evaluating 

economic feasibility, the EPA allows 

consideration of factors such as the 

capital costs, operating and 

maintenance costs, and cost 

effectiveness (i.e., cost per ton of 

pollutant reduced by a measure or 

technology) associated with the measure 

or control.108

Once these analyses are complete, the 

state must use this information to 

develop enforceable control measures 

and submit them to the EPA for 

evaluation as SIP provisions to meet the 

basic requirements of CAA section 110 

and any other applicable substantive 

provisions of the Act. 

2. Summary of the State’s Submission 

and the EPA’s Evaluation and Proposed 

Action 

The control strategy in the SJV PM2.5

Plan is based on ongoing emissions 

reductions from baseline control 

measures. As the term is used here, 

baseline measures are State and District 

regulations adopted prior to the 

development of the SJV PM2.5 Plan that 

continue to achieve emissions 

reductions through the projected 2020 

attainment year and beyond. The 2018 

PM2.5 Plan describes these measures in 

Chapter 4,109 Appendix C (‘‘Stationary 

Source Control Measure Analyses’’), and 

Appendix D (‘‘Mobile Source Control 

Measure Analyses’’). Reductions from 

these baseline measures are 

incorporated into the projected baseline 

inventories and reductions from District 

measures are individually quantified in 

Appendix C. 

The 2018 PM2.5 Plan states that 

mobile sources emit over 85 percent of 

the NOX in the San Joaquin Valley and 

that CARB has adopted and amended 

regulations to reduce public exposure to 

diesel particulate matter, which 

includes direct PM2.5 and NOX, from 

‘‘fuel sources, freight transport sources 

like heavy-duty diesel trucks, 

transportation sources like passenger 

cars and buses, and non-road sources 

like large construction equipment.’’ 110

Given the need for substantial 

emissions reductions from mobile and 

area sources to meet the NAAQS in 

California nonattainment areas, the 

State of California has developed 

stringent control measures for on-road 

and non-road mobile sources and the 

fuels that power them. California has 

unique authority under CAA section 

209 (subject to a waiver or authorization 

as applicable by the EPA) to adopt and 

implement new emissions standards for 

many categories of on-road vehicles and 

engines and new and in-use non-road 

vehicles and engines. The EPA has 

approved such mobile source 

regulations for which waiver 

authorizations have been issued as 

revisions to the California SIP.111

CARB’s mobile source program 

extends beyond regulations that are 

subject to the waiver or authorization 

process set forth in CAA section 209 to 


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112For example, see the EPA’s approval of 

standards and other requirements to control 

emissions from in-use heavy-duty diesel trucks (77 

FR 20308, April 4, 2012), and revisions to the 

California on-road reformulated gasoline and diesel 

fuel regulations (75 FR 26653, May 12, 2010). 

113 2018 PM2.5 Plan, Chapter 4, 4–3. For the 

District’s BACM analysis for stationary and area 

source measures, see 2018 PM2.5 Plan, Appendix C. 

114 Id. at Chapter 4, Table 4–1. 

115 2018 PM2.5 Plan, Chapter 4, section 4.3.1. 

116 Id. at Appendix C., section C.25. 

117 Id. at Appendix D, Chapter II. 

118 Id. at Appendix D, D–127 and D–128. 

include standards and other 

requirements to control emissions from 

in-use heavy-duty trucks and buses, 

gasoline and diesel fuel specifications, 

and many other types of mobile sources. 

Generally, these regulations have also 

been submitted and approved as 

revisions to the California SIP.112

As to stationary and area sources, the 

SJV PM2.5 Plan states that stringent 

regulations adopted for prior attainment 

plans continue to reduce emissions of 

NOX and direct PM2.5.113 Specifically, 

Table 4–1 of the 2018 PM2.5 Plan 

identifies 33 District measures that limit 

NOX and direct PM2.5 emissions from 

stationary and area sources.114

a. Best Available Control Measures 

The State’s BACM demonstration is 

presented in Appendix C (‘‘Stationary 

Source Controls’’) and Appendix D 

(‘‘Mobile Source Control Measure 

Analyses’’) of the 2018 PM2.5 Plan. As 

discussed in section IV.A of this 

proposed rule, Appendix B (‘‘Emissions 

Inventory’’) of the 2018 PM2.5 Plan 

contains the planning inventories for 

direct PM2.5 and all PM2.5 precursors 

(NOX, SOX, VOC, and ammonia) for the 

San Joaquin Valley nonattainment area 

together with documentation to support 

these inventories. Each inventory 

includes emissions from stationary, 

area, on-road, and non-road emission 

sources, and the State specifically 

identifies the condensable component of 

direct PM2.5 for relevant stationary 

source and area source categories. As 

discussed in section IV.B of this 

proposed rule, the State concludes that 

the Plan should control emissions of 

PM2.5 and NOX to reach attainment. 

Accordingly, the BACM and BACT 

evaluation in the Plan addresses 

potential controls for sources of those 

pollutants. 

For stationary and area sources, the 

District identifies the sources of direct 

PM2.5 and NOX in the San Joaquin 

Valley that are subject to District 

emission control measures and provides 

its evaluation of these regulations for 

compliance with BACM requirements in 

Appendix C of the 2018 PM2.5 Plan. As 

part of its process for identifying 

candidate BACM and considering the 

technical and economic feasibility of 

additional control measures, the District 

reviewed the EPA’s guidance 

documents on BACM, additional 

guidance documents on control 

measures for direct PM2.5 and NOX

emission sources, and control measures 

implemented in other ozone and PM2.5

nonattainment areas in California and 

other states.115 The District also 

provides an analysis of several SIPapproved VOC regulations that, 

according to the District, also provide 

ammonia co-benefits.116

For mobile sources, CARB identifies 

the sources of direct PM2.5 and NOX in 

the San Joaquin Valley that are subject 

to the State’s emission control measures 

and provides its evaluation of these 

regulations for compliance with BACM 

requirements in Appendix D of the 2018 

PM2.5 Plan. Appendix D describes 

CARB’s process for determining BACM, 

including identification of the sources 

of direct PM2.5 and NOX in the San 

Joaquin Valley, identification of 

potential control measures for such 

sources, assessment of the stringency 

and feasibility of the potential control 

measures, and adoption and 

implementation of feasible control 

measures.117 Appendix D of the 2018 

PM2.5 Plan also describes the current 

efforts of the eight local jurisdiction 

metropolitan planning organizations 

(MPOs) to implement cost-effective 

transportation control measures (TCMs) 

in the San Joaquin Valley.118

Because we are proposing to 

disapprove the comprehensive 

precursor demonstration in the SJV 

PM2.5 Plan for purposes of the 1997 

annual PM2.5 NAAQS, all precursors to 

the formation of PM2.5 (i.e., NOX, 

ammonia, SOX and VOC) remain PM2.5

plan precursors subject to control 

requirements under subpart 4 of part D, 

title I of the Act for purposes of the 1997 

annual PM2.5 NAAQS in the San Joaquin 

Valley. The SJV PM2.5 Plan contains 

State and District control measures and 

related BACM analyses for sources of 

direct PM2.5 and NOX in the San Joaquin 

Valley but does not contain such 

measures or analyses for sources of SOX

or VOC emissions, given the State’s 

assumption that these precursors would 

not be subject to controls. Furthermore, 

while the District provides an analysis 

of potential control of ammonia sources, 

the Plan does not identify any specific, 

enforceable requirement to reduce 

ammonia emissions in the area and does 

not demonstrate that the State or District 

adequately considered potential control 

measures for ammonia sources, given 

the State’s assumption that ammonia 

would not be subject to controls. 

Without an approvable precursor 

demonstration, the SJV PM2.5 Plan does 

not satisfy BACM and BACT 

requirements for sources of direct PM2.5

and PM2.5 plan precursors for purposes 

of the 1997 annual PM2.5 NAAQS. We 

therefore propose to disapprove the 

BACM/BACT demonstration in the SJV 

PM2.5 Plan for failure to meet the 

requirements of CAA section 

189(b)(1)(B) and 40 CFR 51.1010 for the 

1997 annual PM2.5 NAAQS. 

b. Five Percent Emission Reduction 

Requirement 

The SJV PM2.5 Plan’s demonstration of 

annual five percent reductions in NOX

emissions is in section 5.2 of the 2018 

PM2.5 Plan. As shown in Table 3, the 

demonstration uses the 2013 base year 

inventory as the starting point from 

which the five percent per year 

emission reductions are calculated and 

uses 2017 as the year from which the 

reductions start. The target required 

reduction in 2017 is five percent of the 

base year (2013) inventory, which is 

approximately 15.9 tpd of NOX, and the 

targets for subsequent years are 

additional reductions of five percent 

each year until the 2020 attainment 

year. The projected emissions 

inventories reflect NOX emissions 

reductions achieved by baseline control 

measures and the demonstration shows 

that these NOX emissions reductions are 

greater than the required five percent 

per year. 

TABLE 3—2017–2020 ANNUAL FIVE PERCENT EMISSION REDUCTIONS DEMONSTRATION FOR THE SAN JOAQUIN VALLEY

Year 

% Reduction 

from 2013 

base year 

5% Target 

(tpd NOX) 

CEPAM 

inventory 

v1.05 

(tpd NOX) 

Meets 5%? 

2013 (base year) ............................................................................................. 317.3 


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119Under 40 CFR 51.1000, the applicable 

attainment date is the latest statutory date by which 

an area is required to attain a particular PM2.5

NAAQS or the attainment date approved by the 

EPA as part of an attainment plan for the area. For 

a Serious nonattainment area subject to the 

requirements of CAA section 189(d), the EPA 

establishes the applicable attainment date in 

accordance with the provisions of CAA sections 

179(d)(3) and 172(a)(2). 81 FR 58010, 58103. 

120 81 FR 58010, 58102. 

121Memorandum dated November 29, 2018, from 

Richard Wayland, Air Quality Assessment Division, 

Office of Air Quality Planning and Standards, EPA, 

to Regional Air Division Directors, EPA, Subject: 

‘‘Modeling Guidance for Demonstrating Air Quality 

Goals for Ozone, PM2.5, and Regional Haze,’’ 

(‘‘Modeling Guidance’’), and memorandum dated 

June 28, 2011, from Tyler Fox, Air Quality 

Modeling Group, OAQPS, EPA, to Regional Air 

Program Managers, EPA, Subject: ‘‘Update to the 24 

Hour PM2.5 NAAQS Modeled Attainment Test,’’ 

(‘‘Modeling Guidance Update’’). 

122 In this section, we use the terms ‘‘base case,’’ 

‘‘base year’’ or ‘‘baseline,’’ and ‘‘future year’’ as 

described in section 2.3 of the EPA’s Modeling 

Guidance. The ‘‘base case’’ modeling simulates 

measured concentrations for a given time period, 

using emissions and meteorology for that same year. 

The modeling ‘‘base year’’ (which can be the same 

as the base case year) is the emissions starting point 

for the plan and for projections to the future year, 

both of which are modeled for the attainment 

demonstration. Modeling Guidance, 37–38. 

123Modeling Guidance, section 4.4, ‘‘What is the 

Modeled Attainment Tests for the Annual Average 

PM2.5 NAAQS.’’ 

TABLE 3—2017–2020 ANNUAL FIVE PERCENT EMISSION REDUCTIONS DEMONSTRATION FOR THE SAN JOAQUIN VALLEY— 

Continued 

Year 

% Reduction 

from 2013 

base year 

5% Target 

(tpd NOX) 

CEPAM 

inventory 

v1.05 

(tpd NOX) 

Meets 5%? 

2017 ................................................................................................................. 5 301.3 233.4 Yes. 

2018 ................................................................................................................. 10 285.5 221.5 Yes. 

2019 ................................................................................................................. 15 269.6 214.5 Yes. 

2020 ................................................................................................................. 20 253.8 203.3 Yes. 

Source: 2018 PM2.5 Plan, Table 5–2. 

The State’s methodology for 

calculating the five percent emission 

reduction targets for the years 2017, 

2018, 2019, and 2020 is consistent with 

CAA requirements as interpreted in the 

PM2.5 SIP Requirements Rule, and the 

Plan shows that NOX emissions 

reductions from 2017 to 2020 are greater 

than the required five percent per year. 

However, the language in section 189(d) 

compels us to conclude that the five 

percent demonstration in the Plan does 

not meet that section’s requirement for 

the 1997 annual PM2.5 NAAQS. CAA 

section 189(d) requires that the plan 

provide for annual reductions of PM2.5

or a PM2.5 precursor of not less than five 

percent each year from the date of 

submission of the plan until the 

applicable attainment date approved by 

the EPA.119 The Plan submitted by 

California does not demonstrate 

reductions after 2020 because it projects 

attainment of the 1997 annual PM2.5

NAAQS by December 31, 2020. Because 

the EPA is proposing to disapprove the 

attainment demonstration, as discussed 

in section IV.D, based on ambient 

monitoring data for 2018–2020 

indicating that the San Joaquin Valley 

did not attain the 1997 annual PM2.5

NAAQS by the December 31, 2020 

attainment date projected by the State in 

the SJV PM2.5 Plan, December 31, 2020 

is not the applicable attainment date for 

purposes of the 1997 annual PM2.5

NAAQS in this area, and the Plan does 

not meet the requirement to 

demonstrate five percent reductions per 

year until attainment. Therefore, the 

EPA is proposing to disapprove the 

demonstration of the five percent 

annual emission reductions in the SJV 

PM2.5 Plan for failure to meet the 

requirements of CAA section 189(d) and 

40 CFR 51.1010(c) for the 1997 annual 

PM2.5 NAAQS. 

D. Attainment Demonstration and 

Modeling 

1. Statutory and Regulatory 

Requirements 

Section 189(d) of the CAA requires a 

state with a Serious nonattainment area 

that failed to attain the NAAQS by the 

Serious area attainment date to submit 

a revised attainment demonstration as 

part of a new plan. The PM2.5 SIP 

Requirements Rule explains that the 

same general requirements that apply to 

Moderate and Serious area plans under 

CAA sections 189(a) and 189(b) should 

apply to plans developed pursuant to 

CAA section 189(d)—i.e., the plan must 

include a demonstration (including air 

quality modeling) that the control 

strategy provides for attainment of the 

PM2.5 NAAQS as expeditiously as 

practicable.120 For purposes of 

determining the attainment date that is 

as expeditious as practicable, the state 

must conduct future year modeling that 

takes into account emissions growth, 

known controls (including any controls 

that were previously determined to be 

RACM/RACT or BACM/BACT), the five 

percent per year emissions reductions 

required by CAA section 189(d), and 

any other emissions controls that are 

needed for expeditious attainment of the 

NAAQS. 

The EPA’s PM2.5 modeling 

guidance 121 (‘‘Modeling Guidance’’ and 

‘‘Modeling Guidance Update’’) 

recommends that a photochemical 

model, such as the Comprehensive Air 

Quality Model with Extensions (CAMx) 

or Community Multiscale Air Quality 

Model (CMAQ), be used to simulate a 

base case, with meteorological and 

emissions inputs reflecting a base case 

year, to replicate concentrations 

monitored in that year. The model 

application to the base year undergoes 

a performance evaluation to ensure that 

it satisfactorily corroborates the 

concentrations monitored in that year. 

The model may then be used to simulate 

emissions occurring in other years 

required for a plan, namely the base 

year (which may differ from the base 

case year) and a future year.122 The 

modeled response to the emission 

changes between those years is used to 

calculate RRFs that are applied to the 

design value in the base year to estimate 

the projected design value in the future 

year for comparison against the NAAQS. 

Separate RRFs are estimated for each 

chemical species component of PM2.5, 

and for each quarter of the year, to 

reflect their differing responses to 

seasonal meteorological conditions and 

emissions. Because each species is 

handled separately, before applying an 

RRF, the base year design value must be 

speciated using available chemical 

species measurements—that is, each 

day’s measured PM2.5 design value must 

be split into its species components. 

The Modeling Guidance provides 

additional detail on the recommended 

approach.123

2. Summary of the State’s Submission 

As discussed in section IV.C, the SJV 

PM2.5 Plan includes a modeled 

demonstration projecting that the San 

Joaquin Valley would attain the 1997 


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124NASA, ‘‘Deriving Information on Surface 

conditions from COlumn and VERtically Resolved 

Observations Relevant to Air Quality,’’ available at 

https://www.nasa.gov/mission_pages/discover-aq/ 

index.html. 

125Weight of Evidence Analysis, 26–27, Figure 

12, and Figure 24. 

126 Id. at Figure 16 and Figure 17. 

127 Id. at Figure 21. 

128CMAQ Version 5.0.2. 

annual PM2.5 NAAQS by December 31, 

2020, based on ongoing emissions 

reductions from baseline control 

measures. CARB conducted 

photochemical modeling with the 

CMAQ model using inputs developed 

from routinely available meteorological 

and air quality data, as well as more 

detailed and extensive data from the 

DISCOVER–AQ field study conducted 

in January and February of 2013.124 The 

Plan’s primary discussion of the 

photochemical modeling appears in 

Appendix K (‘‘Modeling Attainment 

Demonstration’’) of the 2018 PM2.5 Plan. 

The State briefly summarizes the area’s 

air quality problem in Chapter 2 (‘‘Air 

Quality Challenges and Trends’’) and 

the modeling results in Chapter 5.3 

(‘‘Attainment Demonstration and 

Modeling’’) of the 2018 PM2.5 Plan. The 

State provides a conceptual model of 

PM2.5 formation in the San Joaquin 

Valley as part of the modeling protocol 

in Appendix L (‘‘Modeling Protocol’’). 

Appendix J (‘‘Modeling Emission 

Inventory’’) describes emission input 

preparation procedures. The State 

presents additional relevant information 

in Appendix C (‘‘Weight of Evidence 

Analysis’’) of the CARB Staff Report, 

which includes ambient trends and 

other data in support of the attainment 

demonstration. 

CARB’s air quality modeling approach 

investigated the many inter-connected 

facets of modeling ambient PM2.5 in the 

San Joaquin Valley, including model 

input preparation, model performance 

evaluation, use of the model output for 

the numerical NAAQS attainment test, 

and modeling documentation. 

Specifically, this required the 

development and evaluation of a 

conceptual model, modeling protocol, 

episode (i.e., base year) selection, 

modeling domain, CMAQ model 

selection, initial and boundary 

condition procedures, meteorological 

model choice and performance, 

modeling emissions inventory 

preparation procedures, model 

performance, attainment test procedure, 

adjustments to baseline air quality for 

modeling, the 2020 attainment test, and 

an unmonitored area analysis. These 

analyses are generally consistent with 

the EPA’s recommendations in the 

Modeling Guidance. 

The model performance evaluation in 

Appendix K includes statistical and 

graphical measures of model 

performance. The magnitude and timing 

of predicted concentrations of total 

PM2.5, as well as of its ammonium and 

nitrate components, generally match the 

occurrence of elevated PM2.5 levels in 

the measured observations. A 

comparison to other recent modeling 

efforts shows good model performance 

on bias, error, and correlation with 

measurements, for total PM2.5 and for 

most of its chemical components. The 

Weight of Evidence Analysis shows the 

downward trend in NOX emissions 

along with a 24 to 44 percent decrease 

in annual PM2.5 design values between 

1999 and 2017.125 The analysis also 

shows decreases in daily PM2.5

concentrations during winter, and in the 

frequency of high PM2.5 concentrations 

generally.126 Available ambient air 

quality data show that total PM2.5 and 

ammonium nitrate concentrations have 

declined over the 2004–2017 period, 

despite some increases from time to 

time.127 These trends show that there 

has been an improvement in air quality 

due to emissions reductions in the San 

Joaquin Valley. 

The State conducted three CMAQ 128

simulations: (1) A 2013 base year 

simulation to demonstrate that the 

model reasonably reproduced the 

observed PM2.5 concentrations in the 

San Joaquin Valley; (2) a 2013 baseline 

year simulation that was the same as the 

2013 base year simulation but excluded 

exceptional event emissions, such as 

wildfire emissions; and (3) a 2020 future 

year simulation that reflects projected 

emissions growth and reductions due to 

controls that have already been adopted 

and implemented. 

Table 4 shows the 2013 base year and 

2020 projected future year annual PM2.5

design values at monitoring sites in the 

San Joaquin Valley. The highest 2020 

projected design value is 14.6 mg/m 3 at 

the Bakersfield—California monitoring 

site, which is below the 15.0 mg/m 3

level of the 1997 annual PM2.5 NAAQS. 

TABLE 4—PROJECTED FUTURE ANNUAL PM2.5 DESIGN VALUES AT MONITORING SITES IN THE SAN JOAQUIN VALLEY

[μg/m3] 

Monitoring site 2013 Base 

design value 

2020 

Projected 

design value 

Bakersfield—California ............................................................................................................................................ 17.2 14.6 

Fresno—Garland ..................................................................................................................................................... 16.9 14.2 

Hanford .................................................................................................................................................................... 16.5 13.3 

Fresno—Hamilton & Winery .................................................................................................................................... 16.2 13.5 

Clovis ....................................................................................................................................................................... 16.1 13.4 

Visalia ...................................................................................................................................................................... 16.0 13.5 

Bakersfield—Planz ................................................................................................................................................... 15.0 12.4 

Madera ..................................................................................................................................................................... 14.9 12.5 

Turlock ..................................................................................................................................................................... 14.2 11.9 

Modesto ................................................................................................................................................................... 13.1 11.4 

Merced–M. Street .................................................................................................................................................... 13.1 10.9 

Stockton ................................................................................................................................................................... 13.0 11.0 

Merced—S Coffee ................................................................................................................................................... 11.0 9.3 

Manteca ................................................................................................................................................................... 10.1 8.7 

Tranquility ................................................................................................................................................................ 7.7 6.4 

Source: 2018 PM2.5 Plan, Table 5–4. 


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129At the time of the EPA’s review, the State had 

not yet certified the 2020 ambient air monitoring 

data. We understand that the State is working to 

certify the data and anticipate that the 2020 data 

will be certified prior to our final action. We do not 

expect the certified data to differ significantly from 

the data reflected in this proposal. 

130Letter dated October 26, 2020, from Gwen 

Yoshimura, Manager, EPA Region 9, Air Quality 

Analysis Office, to Jon Klassen, Director of 

Strategies and Incentives, SJVUAPCD, and letter 

dated November 5, 2020, from Gwen Yoshimura, 

Manager, EPA Region 9, Air Quality Analysis 

Office, to Ravi Ramalingam, Chief, Consumer 

Products and Air Quality Assessment Branch, 

CARB. 

3. The EPA’s Evaluation and Proposed 

Action 

The EPA has reviewed monitoring 

data recorded at air quality monitors 

throughout the San Joaquin Valley PM2.5

nonattainment area to consider whether 

the area attained the 1997 annual PM2.5

NAAQS by the December 31, 2020 

attainment date projected in the SJV 

PM2.5 Plan. We based our review on 

preliminary but complete and qualityassured ambient air monitoring data 

recorded during the three years 

preceding the State’s identified 

attainment date (2018–2020).129 The 

EPA has found that the PM2.5

monitoring network in the San Joaquin 

Valley currently meets or exceeds the 

requirements for the minimum number 

of monitoring sites designated as State 

and Local Air Monitoring Stations 

(SLAMS) for PM2.5 and that CARB’s and 

the District’s annual network plans meet 

the applicable requirements in 40 CFR 

part 58.130

Table 5 shows the annual arithmetic 

means and preliminary annual PM2.5

design values at each of the 18 SLAMS 

monitoring sites within the San Joaquin 

Valley nonattainment area for the most 

recent three-year period (2018–2020). 

The data show that the annual design 

value for the 2018–2020 period ranged 

from 9.5 to 17.6 mg/m 3 across the area 

at monitors with valid design values, 

and that the valid design values 

exceeded 15.0 mg/m 3 (i.e., the level of 

the 1997 annual PM2.5 NAAQS) at eight 

of the monitoring sites, indicating that 

the area did not attain the 1997 annual 

PM2.5 NAAQS by the projected 

December 31, 2020 attainment date. 

As discussed in section IV.D.2, 

CARB’s Weight of Evidence Analysis 

shows a long-term downward trend in 

annual PM2.5 design values through 

2017, the latest year prior to 

development of the SJV PM2.5 Plan for 

which air quality data were available. 

As described in the Weight of Evidence 

Analysis, the San Joaquin Valley has 

shown a general downward trend in 

measured PM2.5 concentrations despite 

the effects of extensive wildfires in 2008 

and unusual meteorological conditions 

during the 2013/2014 winter that 

resulted in higher concentrations during 

those periods. Similarly, the San 

Joaquin Valley area may have 

experienced higher than normal PM2.5

concentrations in 2018 and 2020 due to 

wildfires in the surrounding areas 

during the summer and fall months. 

Table 5 shows that concentrations at all 

17 monitors in the San Joaquin Valley 

area with data spanning 2018 to 2020 

are significantly higher in 2018 and 

2020 relative to concentrations in 2019, 

possibly due to the wildfires in those 

years. 

TABLE 5—2018–2020 ANNUAL PM2.5 DESIGN VALUES FOR THE SAN JOAQUIN VALLEY NONATTAINMENT AREA

County General location site AQS ID 

Annual arithmetic mean 

(μg/m3) 

2018–2020 

Annual 

design values 

(μg/m3) 2018 2019 2020 a

Fresno ........... Fresno—Pacific ......................................... 06–019–5025 17.1 11.2 18.7 15.7 

Fresno—Garland ...................................... 06–019–0011 16.2 11.1 19.2 15.5 

Fresno—Foundry ...................................... 06–019–2016 Inc Inc 20.3 b 20.3 

(Inv) 

Clovis ........................................................ 06–019–5001 14.3 10.3 

(Inc) 

18.4 14.4 

(Inv) 

Tranquility ................................................. 06–019–2009 11.1 5.8 11.5 9.5 

Kern .............. Bakersfield—Planz Road .......................... 06–029–0016 19.4 13.0 20.3 17.6 

Bakersfield—California Ave. ..................... 06–029–0014 17.7 11.9 19.7 16.4 

Bakersfield—Golden State Highway ........ 06–029–0010 18.1 12.4 20.0 16.8 

Kings ............. Corcoran ................................................... 06–031–0004 17.2 12.1 19.5 16.3 

Hanford ..................................................... 06–031–1004 17.7 12.2 19.9 16.6 

Madera .......... Madera—Avenue 14 ................................. 06–039–2010 14.0 9.7 16.9 13.5 

Merced .......... Merced—M Street ..................................... 06–047–2510 14.2 9.6 15.5 13.1 

Merced—Coffee ........................................ 06–047–0003 15.1 9.1 14.7 13.0 

San Joaquin .. Stockton .................................................... 06–077–1002 17.6 9.3 14.4 13.8 

Manteca .................................................... 06–077–2010 13.4 8.3 

(Inc) 

14.8 12.2 

(Inv) 

Stanislaus ..... Modesto .................................................... 06–099–0005 15.2 7.7 14.5 12.5 

Turlock ...................................................... 06–099–0006 17.2 10.7 15.5 14.5 

Tulare ............ Visalia ....................................................... 06–107–2002 17.3 12.9 19.7 16.7 

Source: EPA, Preliminary 2020 AQS Design Value Report, AMP480, accessed June 15, 2021. 

Notes: Inc = Incomplete data. Inv = Invalid design value due to incomplete data. Design values shown in bold type do not meet the 1997 annual PM2.5 NAAQS. aThis preliminary design value includes all available data; no data flagged for exceptional events have been excluded. 

bThe preliminary 2018–2020 design value at Fresno-Foundry (AQS ID: 06–019–2016) is based on concentration data from January 1, 2020 to 

December 31, 2020. The site began operation in 2020; therefore, data from January 1, 2018 to December 31, 2019 are not available. Based on 

40 CFR part 50, Appendix N, section 4.1(b), three years of valid annual means are required to produce a valid annual PM2.5 NAAQS design 

value. Thus, the Fresno-Foundry 2018–2020 preliminary design value is considered invalid. 

Under 40 CFR part 50, appendix N, 

because the 2018–2020 preliminary 

design value exceeded the 15.0 mg/m 3

level of the 1997 annual PM2.5 NAAQS, 

the San Joaquin Valley area did not 

attain the 1997 annual PM2.5 NAAQS by 

December 31, 2020, as projected in the 

SJV PM2.5 Plan. Therefore, the EPA is 

proposing to disapprove the attainment 


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131 General Preamble Addendum, 42015. 

132 Id. at 42016. 

133 Id. 

134 40 CFR 51.1012(a). 

135 81 FR 58010, 58056. 

136 General Preamble Addendum, 42016–42017. 

137 General Preamble, 13539, and General 

Preamble Addendum, 42016. 

138 79 FR 31566 (June 2, 2014) (final rule 

establishing subpart 4 moderate area classifications 

and deadline for related SIP submissions). Although 

this final rule did not affect any action that the EPA 

had previously taken under CAA section 110(k) on 

a SIP for a PM2.5 nonattainment area, the EPA noted 

that states may need to submit additional SIP 

elements to fully comply with the applicable 

requirements of subpart 4, even for areas with 

previously approved PM2.5 attainment plans, and 

that the deadline for any such additional plan 

submissions was December 31, 2014. Id. at 31569. 

139 40 CFR 51.1013(a)(4). 

140 81 FR 58010, 58064. 

141 Id. at 58064 and 58092. 

demonstration in the SJV PM2.5 Plan for 

the 1997 annual PM2.5 NAAQS for 

failure to meet the requirements of CAA 

sections 189(d) and 179(d) and 40 CFR 

51.1011(b). Because our proposal is 

based on ambient monitoring data 

clearly indicating that the Plan was 

insufficient to achieve attainment of the 

1997 annual PM2.5 NAAQS by the 

December 31, 2020 attainment date, we 

do not provide a full evaluation of the 

attainment demonstration analyses for 

these NAAQS at this time. 

E. Reasonable Further Progress and 

Quantitative Milestones 

1. Statutory and Regulatory 

Requirements 

CAA section 172(c)(2) provides that 

all nonattainment area plans shall 

require RFP toward attainment. In 

addition, CAA section 189(c) requires 

that all PM2.5 nonattainment area SIPs 

include quantitative milestones to be 

achieved every three years until the area 

is redesignated to attainment and that 

demonstrate RFP. Section 171(l) of the 

Act defines RFP as ‘‘such annual 

incremental reductions in emissions of 

the relevant air pollutant as are required 

by [Part D] or may reasonably be 

required by the Administrator for the 

purpose of ensuring attainment of the 

applicable [NAAQS] by the applicable 

date.’’ Neither subpart 1 nor subpart 4 

of part D, title I of the Act requires that 

states achieve a set percentage of 

emission reductions in any given year 

for purposes of satisfying the RFP 

requirement. For purposes of the PM2.5

NAAQS, the EPA has interpreted the 

RFP requirement to require that the 

nonattainment area plans show annual 

incremental emission reductions 

sufficient to maintain generally linear 

progress toward attainment by the 

applicable deadline.131

Attainment plans for PM2.5

nonattainment areas should include 

detailed schedules for compliance with 

emission regulations in the area and 

provide corresponding annual emission 

reductions to be achieved by each 

milestone in the schedule.132 In 

reviewing an attainment plan under 

subpart 4, the EPA considers whether 

the annual incremental emission 

reductions to be achieved are reasonable 

in light of the statutory objective of 

timely attainment. Although early 

implementation of the most costeffective control measures is often 

appropriate, states should consider both 

cost-effectiveness and pollution 

reduction effectiveness when 

developing implementation schedules 

for control measures and may 

implement measures that are more 

effective at reducing PM2.5 earlier to 

provide greater public health 

benefits.133

The PM2.5 SIP Requirements Rule 

establishes specific regulatory 

requirements for purposes of satisfying 

the Act’s RFP requirements and 

provides related guidance in the 

preamble to the rule. Specifically, under 

the PM2.5 SIP Requirements Rule, each 

PM2.5 attainment plan must contain an 

RFP analysis that includes, at minimum, 

the following four components: (1) An 

implementation schedule for control 

measures; (2) RFP projected emissions 

for direct PM2.5 and all PM2.5 plan 

precursors for each applicable milestone 

year, based on the anticipated control 

measure implementation schedule; (3) a 

demonstration that the control strategy 

and implementation schedule will 

achieve reasonable progress toward 

attainment between the base year and 

the attainment year; and (4) a 

demonstration that by the end of the 

calendar year for each milestone date for 

the area, pollutant emissions will be at 

levels that reflect either generally linear 

progress or stepwise progress in 

reducing emissions on an annual basis 

between the base year and the 

attainment year.134 Additionally, states 

should estimate the RFP projected 

emissions for each quantitative 

milestone year by sector on a pollutantby-pollutant basis.135

Section 189(c) of the Act requires that 

PM2.5 attainment plans include 

quantitative milestones that 

demonstrate RFP. The purpose of the 

quantitative milestones is to allow 

periodic evaluation of the area’s 

progress towards attainment of the 

NAAQS consistent with RFP 

requirements. Because RFP is an annual 

emission reduction requirement and the 

quantitative milestones are to be 

achieved every three years, when a state 

demonstrates compliance with the 

quantitative milestone requirement, it 

should also demonstrate that RFP has 

been achieved during each of the 

relevant three years. Quantitative 

milestones should provide an objective 

means to evaluate progress toward 

attainment meaningfully, e.g., through 

imposition of emission controls in the 

attainment plan and the requirement to 

quantify those required emission 

reductions. The CAA also requires states 

to submit milestone reports (due 90 

days after each milestone), and these 

reports should include calculations and 

any assumptions made by the state 

concerning how RFP has been met, e.g., 

through quantification of emission 

reductions to date.136

The CAA does not specify the starting 

point for counting the three-year periods 

for quantitative milestones under CAA 

section 189(c). In the General Preamble 

and General Preamble Addendum, the 

EPA interpreted the CAA to require that 

the starting point for the first three-year 

period be the due date for the Moderate 

area plan submission.137 In keeping 

with this historical approach, the EPA 

established December 31, 2014, the 

deadline that the EPA established for a 

state’s submission of any additional 

attainment-related SIP elements 

necessary to satisfy the subpart 4 

Moderate area requirements for the 1997 

PM2.5 NAAQS, as the starting point for 

the first three-year period under CAA 

section 189(c) for the 1997 PM2.5

NAAQS in the San Joaquin Valley.138

Under the PM2.5 SIP Requirements 

Rule, each attainment plan submission 

for an area designated nonattainment for 

the 1997 PM2.5 NAAQS before January 

15, 2015, must contain quantitative 

milestones to be achieved no later than 

three years after December 31, 2014, and 

every three years thereafter until the 

milestone date that falls within three 

years after the applicable attainment 

date.139 If the area fails to attain, this 

post-attainment date milestone provides 

the EPA with the tools necessary to 

monitor the area’s continued progress 

toward attainment while the state 

develops a new attainment plan.140

Quantitative milestones must provide 

for objective evaluation of RFP toward 

timely attainment of the PM2.5 NAAQS 

in the area and include, at minimum, a 

metric for tracking progress achieved in 

implementing SIP control measures, 

including BACM and BACT, by each 

milestone date.141

Because the EPA designated the San 

Joaquin Valley area as nonattainment for 

the 1997 annual PM2.5 NAAQS effective 


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142 70 FR 944 (January 5, 2005). 

143 40 CFR 51.1013(a)(4). 

144As discussed in footnote 32, all references to 

Appendix H in this proposed rule are to the revised 

version submitted on February 11, 2020, which 

replaces the version submitted with the 2018 PM2.5

Plan on May 10, 2019. 

145 Valley State SIP Strategy, Table 7 (identifying 

State measures scheduled for action between 2017 

and 2020, inter alia) and CARB Resolution 18–49, 

‘‘San Joaquin Valley Supplement to the 2016 State 

Strategy for the State Implementation Plan’’ 

(October 25, 2018), 5 (adopting State commitment 

to begin public processes and propose for Board 

consideration the list of proposed SIP measures 

outlined in the Valley State SIP Strategy and 

included in Attachment A, according to the 

schedule set forth therein). 

146 2018 PM2.5 Plan, Appendix H, H–1. 

147 Id. at H–18 and H–19 (District milestones), 

and H–21 and H–22 (State milestones). 

148 Id. at tables H–3 to H–5. 

149 Id. at Table H–6. 

150 Id. at Table H–7. 

151 Id. at Table H–12. 

152 Id. at Table H–8. 

153 Id. at H–18 and H–19 (District milestones), 

and H–21 and H–22 (State milestones). 

154 Id. We note that the District’s identified 

quantitative milestones for 2023 appear to contain 

a typographical error, as they include a District 

report on ‘‘[t]he status of SIP measures adopted 

between 2017 and 2020 as per the schedule 

included in the adopted Plan.’’ Id. at H–18 and H– 

19. We understand that the District intended to 

refer here to the status of SIP measures adopted 

between 2020 and 2023, consistent with the 

schedule in the 2018 PM2.5 Plan. 

155 Id. at H–18 and H–19 (District milestones), 

and H–21 and H–22 (State milestones). 

156Letter dated December 20, 2018, from Richard 

W. Corey, Executive Officer, CARB, to Michael 

Stoker, Regional Administrator, EPA Region 9, with 

attachment ‘‘2017 Quantitative Milestone Report for 

the 1997 and 2006 NAAQS.’’ 

157Letter dated February 15, 2021, from Deborah 

Jordan, Acting Regional Administrator, EPA Region 

IX, to Richard W. Corey, Executive Officer, CARB, 

with enclosure titled ‘‘EPA Evaluation of 2017 

Quantitative Milestone Report.’’ 

158 Id. 

April 5, 2005,142 the plan for this area 

must contain quantitative milestones to 

be achieved no later than three years 

after December 31, 2014 (i.e., by 

December 31, 2017), and every three 

years thereafter until the milestone date 

that falls within three years after the 

applicable attainment date.143

2. Summary of the State’s Submission 

Appendix H (‘‘RFP, Quantitative 

Milestones, and Contingency’’) of the 

2018 PM2.5 Plan contains the State’s RFP 

demonstration and quantitative 

milestones for the 1997 annual PM2.5

NAAQS,144 and the Valley State SIP 

Strategy contains the control measure 

commitments that CARB has identified 

as mobile source quantitative milestones 

for the 2020 milestone date.145 Given 

the State’s conclusions that ammonia, 

SOX, and VOC emissions do not 

contribute significantly to PM2.5 levels 

that exceed the 1997 annual PM2.5

NAAQS in the San Joaquin Valley, as 

discussed in section IV.B of this 

proposed rule, the RFP demonstration 

provided by the State addresses 

emissions of direct PM2.5 and NOX.146

Similarly, the State developed 

quantitative milestones based upon 

implementation of control strategy 

measures in the adopted SIP and in the 

SJV PM2.5 Plan that achieve reductions 

in emissions of direct PM2.5 and NOX.147

For the 1997 annual PM2.5 NAAQS, the 

RFP demonstration in the Plan shows 

generally linear progress toward 

attainment. 

We describe the RFP demonstration 

and quantitative milestones in the SJV 

PM2.5 Plan in greater detail below. 

Reasonable Further Progress 

The State addresses the RFP and 

quantitative milestone requirements in 

Appendix H to the 2018 PM2.5 Plan 

submitted in February 2020. The Plan 

estimates that emissions of direct PM2.5

and NOX will generally decline from the 

2013 base year to the projected 2020 

attainment year, and beyond to the 2023 

post-attainment quantitative milestone 

year. The Plan’s emissions inventory 

shows that direct PM2.5 and NOX are 

emitted by a large number and range of 

sources in the San Joaquin Valley. Table 

H–2 in Appendix H contains an 

anticipated implementation schedule 

for District regulatory control measures 

and Table 4–8 in Chapter 4 of the 2018 

PM2.5 Plan contains an anticipated 

implementation schedule for CARB 

control measures in the San Joaquin 

Valley. Table H–5 in Appendix H 

contains projected emissions for each 

quantitative milestone year. These 

emission levels reflect baseline emission 

projections through the 2023 postattainment milestone year.148

The SJV PM2.5 Plan identifies 

emission reductions needed for 

attainment of the 1997 annual PM2.5

NAAQS by 2020,149 and identifies San 

Joaquin Valley’s progress toward 

attainment in each milestone year.150

The State and District set RFP targets for 

each of the quantitative milestone years 

as shown in Table H–8 of Appendix H 

of the 2018 PM2.5 Plan. 

According to the Plan, reductions in 

both direct PM2.5 and NOX emissions 

from 2013 base year levels result in 

emission levels consistent with 

attainment in the 2020 attainment year. 

Based on these analyses, the State and 

District conclude that the adopted 

control strategy is adequate to meet the 

RFP requirement for the 1997 annual 

PM2.5 NAAQS. 

Quantitative Milestones 

Appendix H of the 2018 PM2.5 Plan 

identifies the milestone dates of 

December 31, 2017, December 31, 2020, 

and December 31, 2023, for the 1997 

PM2.5 NAAQS.151 Appendix H also 

identifies target emission levels to meet 

the RFP requirement for direct PM2.5

and NOX emissions for each of these 

milestone years,152 and State and 

District control measures that will 

achieve emission reductions in the years 

leading up to each of the milestones, in 

accordance with the control strategy in 

the Plan.153

The Plan includes quantitative 

milestones for mobile, stationary, and 

area sources. For mobile sources, CARB 

has developed quantitative milestones 

that provide for an evaluation of RFP 

based on the implementation of specific 

control measures by the relevant threeyear milestones. For each quantitative 

milestone year, the Plan provides for 

evaluating RFP by tracking State and 

District implementation of regulatory 

measures and SIP commitments during 

the three-year period leading to each 

milestone date, consistent with the 

control strategy in the SJV PM2.5

Plan.154 The identified regulatory 

measures include State measures for 

light-duty vehicles and non-road 

vehicles and several District measures 

for stationary and area sources.155

CARB submitted its 2017 Quantitative 

Milestone Report for the San Joaquin 

Valley to the EPA on December 20, 

2018.156 The report includes a 

certification that CARB and the District 

met the 2017 quantitative milestones 

identified in the SJV PM2.5 Plan for the 

1997 PM2.5 NAAQS and discusses the 

State’s and District’s progress on 

implementing the three CARB measures 

and six District measures identified in 

Appendix H as quantitative milestones 

for the 2017 milestone year. On 

February 15, 2021, the EPA determined 

that the 2017 Quantitative Milestone 

Report was adequate.157 In our 

evaluation of the 2017 Quantitative 

Milestone Report, we found that the 

control measures in the Plan are in 

effect, consistent with the RFP 

demonstration in the SJV PM2.5 Plan for 

the 1997 annual PM2.5 NAAQS, but we 

noted that the determination of 

adequacy did not constitute approval of 

any component of the SJV PM2.5 Plan.158

3. The EPA’s Evaluation and Proposed 

Action 

As discussed in section IV.D, we are 

proposing to disapprove the attainment 

demonstration for the 1997 annual PM2.5

NAAQS in the SJV PM2.5 Plan because 

the area did not attain by the State’s 

projected attainment date, which was 

December 31, 2020. As a result, the RFP 


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159 40 CFR 51.1014(a). 160 81 FR 58010, 58066 and General Preamble 

Addendum, 42015. 

161 81 FR 58010, 58066. See also General 

Preamble, 13512, 13543–13544, and General 

Preamble Addendum, 42014–42015. 162Bahr v. EPA, 836 F.3d 1218, 1235–1237 (9th 

Cir. 2016). 163Letter dated October 23, 2017, from Richard 

W. Corey, Executive Officer, CARB, to Alexis 

Strauss, Acting Regional Administrator, EPA Region 

9. 164Letter dated March 19, 2021, from Richard W. 

Corey, Executive Officer, CARB, to Deborah Jordan, 

Acting Regional Administrator, EPA Region 9, 

transmitting CARB Executive Order S–21–004. 165 2018 PM2.5 Plan, Appendix H, H–25. 166 85 FR 44206 (July 22, 2020) (final approval of 

Rule 4901); 85 FR 1131, 1132–1133 (January 9, 

2020) (proposed approval of Rule 4901). 

demonstration in the Plan does not 

achieve the statutory purpose of RFP to 

‘‘ensure attainment’’ under CAA section 

171(l) and the quantitative milestones 

do not ‘‘demonstrate [RFP] toward 

attainment by the applicable date’’ 

under CAA section 189(c). We are, 

therefore, proposing to disapprove the 

RFP and quantitative milestone 

elements of the SJV PM2.5 Plan for the 

1997 annual PM2.5 NAAQS for failure to 

meet the requirements of CAA sections 

172(c)(2), 171(1), and 189(c) and 40 CFR 

51.1012 and 51.1013. 

F. Contingency Measures 

1. Requirements for Contingency 

Measures 

Under CAA section 172(c)(9), each 

state required to make a nonattainment 

plan SIP submission must include, in 

such plan, contingency measures to be 

implemented if an area fails to meet RFP 

(‘‘RFP contingency measures’’) or fails 

to attain the NAAQS by the applicable 

attainment date (‘‘attainment 

contingency measures’’). Under the 

PM2.5 SIP Requirements Rule, states 

must include contingency measures that 

will be implemented following a 

determination by the EPA that the state 

has failed: (1) To meet any RFP 

requirement in the approved SIP; (2) to 

meet any quantitative milestone in the 

approved SIP; (3) to submit a required 

quantitative milestone report; or (4) to 

attain the applicable PM2.5 NAAQS by 

the applicable attainment date.159

Contingency measures must be fully 

adopted rules or control measures that 

are ready to be implemented quickly 

upon failure to meet RFP or failure of 

the area to meet the relevant NAAQS by 

the applicable attainment date.160

The purpose of contingency measures 

is to continue progress in reducing 

emissions while a state revises its SIP to 

meet the missed RFP requirement or to 

correct ongoing nonattainment. Neither 

the CAA nor the EPA’s implementing 

regulations establish a specific level of 

emission reductions that 

implementation of contingency 

measures must achieve, but the EPA 

recommends that contingency measures 

should provide for emission reductions 

equivalent to approximately one year of 

reductions needed for RFP in the 

nonattainment area at issue, calculated 

as the overall level of reductions needed 

to demonstrate attainment divided by 

the number of years from the base year 

to the attainment year. In general, we 

expect all actions needed to effect full 

implementation of the measures to 

occur within 60 days after the EPA 

notifies the state of a failure to meet RFP 

or to attain.161

To satisfy the requirements of 40 CFR 

51.1014, the contingency measures 

adopted as part of a PM2.5 attainment 

plan must consist of control measures 

for the area that are not otherwise 

required to meet other nonattainment 

plan requirements (e.g., to meet RACM/ 

RACT requirements) and must specify 

the timeframe within which their 

requirements become effective following 

any of the EPA determinations specified 

in 40 CFR 51.1014(a). In a 2016 decision 

called Bahr v. EPA (‘‘Bahr’’),162 the 

Ninth Circuit Court of Appeals rejected 

the EPA’s interpretation of CAA section 

172(c)(9) to allow approval of alreadyimplemented control measures as 

contingency measures. In Bahr, the 

Ninth Circuit concluded that 

contingency measures must be measures 

that are triggered and implemented only 

after the EPA determines that an area 

failed to meet RFP requirements or to 

attain by the applicable attainment date. 

Thus, within the geographic jurisdiction 

of the Ninth Circuit, already 

implemented measures cannot serve as 

contingency measures under CAA 

section 172(c)(9). To comply with 

section 172(c)(9), a state must develop, 

adopt, and submit a contingency 

measure to be triggered upon a failure 

to meet an RFP milestone, failure to 

meet a quantitative milestone 

requirement, or failure to attain the 

NAAQS by the applicable attainment 

date. 

2. Summary of the State’s Submission 

The SJV PM2.5 Plan addresses the 

contingency measure requirement for 

the 1997 annual PM2.5 NAAQS in 

section 5.6 and Appendix H 

(specifically, section H.3 (‘‘Contingency 

Measures’’)) of the 2018 PM2.5 Plan. The 

Plan relies on revisions to the District’s 

wood-burning rule (Rule 4901) and 

refers to a SIP revision submitted by 

CARB on October 23, 2017, titled ‘‘State 

Implementation Plan Attainment 

Contingency Measures for the San 

Joaquin Valley 15 mg/m 3 Annual PM2.5

NAAQS’’ (‘‘2017 Contingency Measure 

SIP’’).163 On March 19, 2021, CARB 

withdrew the 2017 Contingency 

Measure SIP submission.164 Therefore, 

we are not evaluating the 2017 

Contingency Measure SIP as part of this 

action. 

With respect to the District 

contingency measure, the 2018 PM2.5

Plan states that the District will amend 

Rule 4901 to include a requirement that 

would be triggered upon a 

determination by the EPA that the San 

Joaquin Valley failed to meet a 

regulatory requirement necessitating 

implementation of a contingency 

measure.165 As discussed in section II.C, 

the District adopted amendments to 

Rule 4901 on June 20, 2019, including 

a contingency measure in section 5.7.3 

of the amended rule. In the EPA’s July 

22, 2020 final action to approve Rule 

4901, as amended June 20, 2019, we did 

not evaluate section 5.7.3 of the 

amended rule for compliance with CAA 

requirements for contingency 

measures.166 We are now evaluating 

section 5.7.3 of Rule 4901 for 

compliance with the requirements for 

contingency measures for purposes of 

the 1997 annual PM2.5 NAAQS. 

Rule 4901 is designed to limit 

emissions generated by the use of wood 

burning fireplaces, wood burning 

heaters, and outdoor wood burning 

devices. The rule establishes 

requirements for the sale/transfer, 

operation, and installation of wood 

burning devices and for advertising the 

sale of seasoned wood consistent with a 

moisture content limit within the San 

Joaquin Valley. The rule includes a twotiered, episodic wood burning 

curtailment requirement that applies 

during four winter months, November 

through February. During a level one 

episodic wood burning curtailment, 

section 5.7.1 prohibits any person from 

operating a wood burning fireplace or 

unregistered wood burning heater, but 

permits the use of a properly operated 

wood burning heater that meets 

certification requirements and has a 

current registration with the District. 

Sections 5.9 through 5.11 impose 

specific registration requirements on 

any person operating a wood burning 

fireplace or wood burning heater and 

section 5.12 imposes specific 

certification requirements on wood 

burning heater professionals. During a 

level two episodic wood burning 

curtailment, operation of any wood 

burning device is prohibited by section 

5.7.2. 

Prior to the 2019–2020 wood burning 

season, the District imposed a level one 


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167See Table B–13 in Appendix B from the 

District’s Final Staff Report (June 20, 2019) for 

revisions to Rule 4901. 

168NOX emissions reductions from the 

contingency measure are based on the District’s 

estimates for direct PM2.5 emissions using the ratio 

of direct PM2.5 to NOX in Table 1, page 8, of the 

District’s Final Staff Report (June 20, 2019) for 

revisions to Rule 4901. 

169 85 FR 44206 (July 22, 2020). 

170Section 5.7.3 of Rule 4901 states that ‘‘the 

District shall notify the public of an Episodic 

Curtailment for the PM2.5 curtailment levels 

described in Sections 5.7.1.2 and 5.7.2.2 for any 

county that has failed to attain the applicable 

standard.’’ (emphasis added) We interpret this to 

mean that the District would apply the more 

stringent curtailment provisions for any county 

identified in the EPA’s final rule making the 

determination that the San Joaquin Valley failed to 

attain the applicable PM2.5 NAAQS. 

171 85 FR 44206 (final approval of Rule 4901) and 

85 FR 44192 (determination that Rule 4901 

Continued 

curtailment when the PM2.5

concentration was forecasted to be 

between 20 mg/m 3 and 65 mg/m 3 and 

imposed a level two curtailment when 

the PM2.5 concentration was forecasted 

to be above 65 mg/m 3 or the PM10

concentration was forecasted to be 

above 135 mg/m 3. In 2019 the District 

adopted revisions to Rule 4901 to lower 

the wood burning curtailment 

thresholds in the ‘‘hot spot’’ counties of 

Madera, Fresno, and Kern. The District 

lowered the level one PM2.5 threshold 

for these three counties from 20 mg/m 3

to 12 mg/m 3, and the level two PM2.5

threshold from 65 mg/m 3 to 35 mg/m 3. 

The District did not modify the 

curtailment thresholds for other 

counties in the San Joaquin Valley— 

those levels remain at 20 mg/m 3 for level 

one and 65 mg/m 3 for level two. 

The District’s 2019 revision to Rule 

4901 also included the addition of a 

contingency measure in section 5.7.3 of 

the rule, requiring that 60 days 

following the effective date of an EPA 

determination that the San Joaquin 

Valley has failed to attain the 1997, 

2006, or 2012 PM2.5 NAAQS by the 

applicable attainment date, the PM2.5

curtailment levels of any county that 

has failed to attain the applicable 

standard will be lowered to the 

curtailment levels in place for hot spot 

counties. The District estimates that the 

potential emissions reduction of direct 

PM2.5 would be in the range of 0.014 tpd 

(if the contingency measure is triggered 

in Kings County but not the other nonhot spot counties) to 0.387 tpd (if the 

contingency measure is triggered in all 

five of the non-hot spot counties), but 

there would be no emissions reduction 

if, at the time of the determination of 

failure to attain the 1997 annual PM2.5

NAAQS by the attainment date, 

violations of the 1997 annual PM2.5

NAAQS are observed only at monitors 

in the hot spot counties.167 The 

corresponding potential NOX emissions 

reduction would be in the range of 0.002 

tpd to 0.060 tpd, respectively, but once 

again, there would be no emissions 

reduction if the violations are monitored 

in the hot spot counties only.168 The 

EPA has already approved Rule 4901, as 

amended in 2019, as a revision to the 

California SIP.169

Appendix H of the 2018 PM2.5 Plan 

also provides updated emissions 

estimates for the year following the 

State’s projected attainment year (i.e., 

2021) to evaluate whether the emission 

reductions from the contingency 

measures are sufficient. Table H–3 in 

Appendix H of the 2018 PM2.5 Plan 

shows that the emission reductions 

between 2020 and 2021 are estimated to 

be 0.5 tpd of direct PM2.5 and 12.3 tpd 

of NOX (based on the annual average 

inventory). 

3. The EPA’s Evaluation and Proposed 

Action 

We have evaluated the contingency 

provision in Rule 4901 (i.e., section 

5.7.3 of the rule) for compliance with 

the requirements of CAA section 

172(c)(9) and 40 CFR 51.1014 and find 

that the measure meets some, but not 

all, of the applicable requirements for 

contingency measures. The contingency 

provision in Rule 4901 is structured to 

be undertaken if the area fails to attain 

the 1997 PM2.5 NAAQS, not before, and 

therefore is consistent with the Bahr 

decision disallowing alreadyimplemented measures for contingency 

measure purposes under CAA section 

172(c)(9). Furthermore, the contingency 

provision in Rule 4901 would achieve 

emission reductions above and beyond 

those that are projected to be achieved 

if the EPA finds that monitoring 

locations in counties outside of Fresno, 

Kern, or Madera counties (i.e., the ‘‘hot 

spot’’ counties listed in the rule) are 

violating the 1997 annual PM2.5 NAAQS 

as of the attainment date. In accordance 

with 40 CFR 51.1014, the contingency 

provision in Rule 4901 identifies a 

specific triggering mechanism. In this 

case, the triggering mechanism in the 

rule is the EPA’s final determination 

that San Joaquin Valley has failed to 

attain the 1997 annual PM2.5 NAAQS by 

the applicable attainment date.170 The 

rule also specifies a timeframe within 

which its requirements become effective 

after a failure-to-attain determination 

(i.e., 60 days from the effective date of 

the EPA’s final determination), and 

would take effect with minimal further 

action by the State or the EPA. 

Conversely, we have identified 

several deficiencies with respect to the 

contingency measure element of the SJV 

PM2.5 Plan. First, the contingency 

provisions of Rule 4901 do not address 

the potential for State failures to meet 

RFP, to meet a quantitative milestone, or 

to submit a quantitative milestone 

report. In addition, the contingency 

measure provisions of Rule 4901 are not 

structured to achieve any additional 

emissions reductions if the EPA finds 

that the monitoring locations in the ‘‘hot 

spot’’ counties (i.e., Fresno, Kern, or 

Madera) are the only counties in the San 

Joaquin Valley that are violating the 

1997 annual PM2.5 NAAQS as of the 

attainment date. To qualify as a 

contingency measure, a measure must 

be structured to achieve emissions 

reductions if triggered; however, the 

contingency provisions of Rule 4901 

provide for such reductions only under 

certain circumstances. Thus, the 

contingency provisions of Rule 4901 

should be revised to provide for 

additional emissions reductions in the 

San Joaquin Valley (if triggered) 

regardless of which monitoring site(s) is 

determined to be violating the 1997 

annual PM2.5 NAAQS as of the 

attainment date. 

Furthermore, CAA section 172(c)(9) 

requires that the plan provide for the 

implementation of contingency 

measures to be undertaken if the area 

fails to attain the 1997 annual PM2.5

NAAQS by the applicable attainment 

date. Given our proposed disapproval of 

the State’s attainment demonstration for 

the 1997 annual PM2.5 NAAQS, as 

described in section IV.D.3 of this 

proposed rule, it is not possible to 

determine whether emission reductions 

from contingency measures in the SJV 

PM2.5 Plan that are intended to take 

effect upon an EPA finding that the area 

failed to attain the standards are in fact 

surplus to the attainment 

demonstration, as required by section 

172(c)(9). 

For these reasons, we are proposing to 

disapprove the contingency measure 

element of the SJV PM2.5 Plan for the 

1997 annual PM2.5 NAAQS. If we 

finalize this proposal, we will remove 

from the California SIP the contingency 

provision in Rule 4901 (section 5.7.3) 

because this provision does not satisfy 

CAA requirements for contingency 

measures and is severable from the 

remainder of Rule 4901. The 

disapproval of section 5.7.3 of Rule 

4901 would have no effect on our prior 

approval of the rule for purposes of 

meeting the BACM and MSM 

requirements for the 2006 PM2.5 NAAQS 

in the San Joaquin Valley,171 which 


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implements BACM and MSM for residential wood 

burning). 

172 40 CFR 93.118(e)(4)(v). 

173 40 CFR 51.1012(a), 51.1013(a)(1). 

174 40 CFR 51.1013(a)(4) and 81 FR 58010, 58058 

and 58063–58064 (August 24, 2016). 

175 81 FR 58010, 58063–58064. 

176 40 CFR 93.102(b)(3), 93.102(b)(2)(v), and 

93.122(f); see also Conformity Rule preambles at 69 

FR 40004, 40031–40036 (July 1, 2004), 70 FR 24280, 

24283–24285 (May 6, 2005) and 70 FR 31354 (June 

1, 2005). 

177 40 CFR 93.102(b)(2)(iv). 

178 40 CFR 93.109(f). 

179 69 FR 40004. 

would remain in effect for all but 

section 5.7.3 of Rule 4901. 

G. Motor Vehicle Emission Budgets 

1. Statutory and Regulatory 

Requirements 

Section 176(c) of the CAA requires 

federal actions in nonattainment and 

maintenance areas to conform to the 

goals of the state’s SIP to eliminate or 

reduce the severity and number of 

violations of the NAAQS and achieve 

timely attainment of the standards. 

Conformity to the SIP’s goals means that 

such actions will not: (1) Cause or 

contribute to violations of a NAAQS, (2) 

worsen the severity of an existing 

violation, or (3) delay timely attainment 

of any NAAQS or any interim 

milestone. 

Actions involving Federal Highway 

Administration (FHWA) or Federal 

Transit Administration (FTA) funding 

or approval are subject to the EPA’s 

transportation conformity rule, codified 

at 40 CFR part 93, subpart A. Under this 

rule, metropolitan planning 

organizations (MPOs) in nonattainment 

and maintenance areas coordinate with 

state and local air quality and 

transportation agencies, the EPA, the 

FHWA, and the FTA to demonstrate that 

an area’s regional transportation plans 

(RTPs) and transportation improvement 

programs conform to the applicable SIP. 

This demonstration is typically done by 

showing that estimated emissions from 

existing and planned highway and 

transit systems are less than or equal to 

the motor vehicle emissions budgets 

(MVEBs or ‘‘budgets’’) contained in all 

control strategy SIPs. Budgets are 

generally established for specific years 

and specific pollutants or precursors 

and must reflect all of the motor vehicle 

control measures contained in the 

attainment and RFP demonstrations.172

Under the PM2.5 SIP Requirements 

Rule, Serious area PM2.5 attainment 

plans must include appropriate 

quantitative milestones and projected 

RFP emission levels for direct PM2.5 and 

all PM2.5 plan precursors in each 

milestone year.173 For an area 

designated nonattainment for the 1997 

PM2.5 NAAQS before January 15, 2015, 

the attainment plan must contain 

quantitative milestones to be achieved 

no later than three years after December 

31, 2014, and every three years 

thereafter until the milestone date that 

falls within three years after the 

applicable attainment date.174 As the 

EPA explained in the preamble to the 

PM2.5 SIP Requirements Rule, it is 

important to include a post-attainment 

year quantitative milestone to ensure 

that, if the area fails to attain by the 

attainment date, the EPA can continue 

to monitor the area’s progress toward 

attainment while the state develops a 

new attainment plan.175 Although the 

post-attainment year quantitative 

milestone is a required element of a 

Serious area plan, it is not necessary to 

demonstrate transportation conformity 

for 2023 or to use the 2023 budgets in 

transportation conformity 

determinations until such time as the 

area fails to attain the 1997 annual PM2.5

NAAQS. 

PM2.5 plans should identify budgets 

for direct PM2.5, NOX, and all other 

PM2.5 precursors for which on-road 

emissions are determined to 

significantly contribute to PM2.5 levels 

in the area for each RFP milestone year 

and the attainment year, if the plan 

demonstrates attainment. All direct 

PM2.5 SIP budgets should include direct 

PM2.5 motor vehicle emissions from 

tailpipes, brake wear, and tire wear. 

With respect to PM2.5 from re-entrained 

road dust and emissions of VOC, SO2, 

and/or ammonia, the transportation 

conformity provisions of 40 CFR part 

93, subpart A, apply only if the EPA 

Regional Administrator or the director 

of the state air agency has made a 

finding that emissions of these 

pollutants within the area are a 

significant contributor to the PM2.5

nonattainment problem and has so 

notified the MPO and Department of 

Transportation (DOT), or if the 

applicable implementation plan (or 

implementation plan submission) 

includes any of these pollutants in the 

approved (or adequate) budget as part of 

the RFP, attainment, or maintenance 

strategy.176

By contrast, transportation conformity 

requirements apply with respect to 

emissions of NOX unless both the EPA 

Regional Administrator and the director 

of the state air agency have made a 

finding that transportation-related 

emissions of NOX within the 

nonattainment area are not a significant 

contributor to the PM2.5 nonattainment 

problem and have so notified the MPO 

and DOT, or the applicable 

implementation plan (or 

implementation plan submission) does 

not establish an approved (or adequate) 

budget for such emissions as part of the 

RFP, attainment, or maintenance 

strategy.177

It is not always necessary for states to 

establish motor vehicle emissions 

budgets for all PM2.5 precursors. The 

PM2.5 SIP Requirements Rule allows a 

state to demonstrate that emissions of 

certain precursors do not contribute 

significantly to PM2.5 levels that exceed 

the NAAQS in a nonattainment area, in 

which case the state may exclude such 

precursor(s) from its control evaluations 

for the specific NAAQS at issue. If a 

state successfully demonstrates that the 

emissions of one or more of the PM2.5

precursors from all sources do not 

contribute significantly to PM2.5 levels 

in the subject area, then it is not 

necessary to establish motor vehicle 

emissions budgets for such precursor(s). 

Alternatively, the transportation 

conformity regulations contain criteria 

for determining whether emissions of 

one or more PM2.5 precursors are 

insignificant for transportation 

conformity purposes.178 For a pollutant 

or precursor to be considered an 

insignificant contributor based on the 

transportation conformity rule’s criteria, 

the control strategy SIP must 

demonstrate that it would be 

unreasonable to expect that such an area 

would experience enough motor vehicle 

emissions growth in that pollutant and/ 

or precursor for a NAAQS violation to 

occur. Insignificance determinations are 

based on factors such as air quality, SIP 

motor vehicle control measures, trends 

and projections of motor vehicle 

emissions, and the percentage of the 

total attainment plan emissions 

inventory for the NAAQS at issue that 

is comprised of motor vehicle 

emissions. The EPA’s rationale for 

providing for insignificance 

determinations is described in the July 

1, 2004 revision to the Transportation 

Conformity Rule.179

Transportation conformity trading 

mechanisms are allowed under 40 CFR 

93.124 where a state establishes 

appropriate mechanisms for such trades. 

The basis for the trading mechanism is 

the SIP attainment modeling that 

establishes the relative contribution of 

each PM2.5 precursor pollutant. The 

applicability of emission trading 

between conformity budgets for 

conformity purposes is described in 40 

CFR 93.124(c). 

The EPA’s process for determining the 

adequacy of a budget consists of three 


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180 40 CFR 93.118(f)(1). 

181 40 CFR 93.118(f)(2). 

182 2018 PM2.5 Plan, Appendix D, Table 3–1. 

183 40 CFR 93.124(c) and (d). 

184 2018 PM2.5 Plan, Appendix D, D–122 to D– 

123. 185 2018 PM2.5 Plan, Appendix D, D–121 and D– 

122. 

186 40 CFR 93.109(f). 

187Letter dated May 9, 2019, from Richard W. 

Corey, Executive Officer, CARB, to Mike Stoker, 

Regional Administrator, EPA Region 9, 3. 

188 2018 PM2.5 Plan, Appendix D, D–126 and D– 

127. 

basic steps: (1) Notifying the public of 

a SIP submittal; (2) providing the public 

the opportunity to comment on the 

budget during a public comment period; 

and, (3) making a finding of adequacy or 

inadequacy. The EPA can notify the 

public by either posting an 

announcement that the EPA has 

received SIP budgets on the EPA’s 

adequacy website,180 or through a 

Federal Register notice of proposed 

rulemaking when the EPA reviews the 

adequacy of an implementation plan 

budget simultaneously with its review 

and action on the SIP itself.181

2. Summary of the State’s Submission 

The 2018 PM2.5 Plan includes budgets 

for direct PM2.5 and NOX emissions, 

calculated using annual average daily 

emissions, for 2017, 2020, and 2023 

(RFP milestone year, attainment year, 

and post-attainment quantitative 

milestone year, respectively).182 The 

Plan establishes separate direct PM2.5

and NOX subarea budgets for each 

county, or partial county (for Kern 

County), in the San Joaquin Valley.183

CARB calculated the budgets using 

EMFAC2014, CARB’s latest version of 

the EMFAC model for estimating 

emissions from on-road vehicles 

operating in California that was 

available at the time of Plan 

development, and the latest modeled 

vehicle miles traveled and speed 

distributions from the San Joaquin 

Valley MPOs from the Final 2017 

Federal Transportation Improvement 

Program, adopted in September 2016. 

The budgets reflect annual average 

emissions because those emissions are 

linked with the District’s attainment 

demonstration for the 1997 annual PM2.5

NAAQS. 

The direct PM2.5 budgets include 

tailpipe, brake wear, and tire wear 

emissions but do not include paved 

road dust, unpaved road dust, and road 

construction dust emissions.184 The 

State is not required to include reentrained road dust in the budgets 

under section 93.103(b)(3) unless the 

EPA or the State has made a finding that 

these emissions are significant. Neither 

the State nor the EPA has made such a 

finding, but the Plan does include a 

discussion of the significance/ 

insignificance factors for re-entrained 

road dust.185 The budgets included in 

the 2018 PM2.5 Plan for purposes of the 

1997 annual PM2.5 NAAQS are shown in 

Table 6. 

TABLE 6—MOTOR VEHICLE EMISSION BUDGETS FOR THE SAN JOAQUIN VALLEY FOR THE 1997 ANNUAL PM2.5 NAAQS 

[Annual average, tpd] 

County 

2017 

(RFP year) 

2020 

(Attainment year) 

2023 

(Post-attainment year) 

PM2.5 NOX PM2.5 NOX PM2.5 NOX

Fresno .............................................................................. 0.9 28.5 0.9 25.3 0.8 15.1 

Kern .................................................................................. 0.8 28.0 0.8 23.3 0.7 13.3 

Kings ................................................................................ 0.2 5.8 0.2 4.8 0.2 2.8 

Madera ............................................................................. 0.2 5.3 0.2 4.2 0.2 2.5 

Merced ............................................................................. 0.3 10.7 0.3 8.9 0.3 5.3 

San Joaquin ..................................................................... 0.7 14.9 0.6 11.9 0.6 7.6 

Stanislaus ......................................................................... 0.4 11.9 0.4 9.6 0.4 6.1 

Tulare ............................................................................... 0.4 10.8 0.4 8.5 0.4 5.2 

Source: 2018 PM2.5 Plan, Appendix D, Table 3–1. Budgets are rounded to the nearest tenth of a ton. 

The State did not include budgets for 

VOC, SO2, or ammonia. As discussed in 

section IV.B of this proposed rule, the 

State submitted a PM2.5 precursor 

demonstration documenting its 

conclusion that control of these 

precursors would not significantly 

contribute to attainment of the 1997 

annual PM2.5 NAAQS. The State also 

included a discussion of the 

significance/insignificance factors for 

ammonia, SO2, and VOC to demonstrate 

a finding of insignificance under the 

transportation conformity rule.186

In the submittal letter for the 2018 

PM2.5 Plan, CARB requested that the 

EPA limit the duration of the approval 

of the budgets to the period before the 

effective date of the EPA’s adequacy 

finding for any subsequently submitted 

budgets.187

Conformity Trading Mechanism 

The 2018 PM2.5 Plan also includes a 

proposed trading mechanism for 

transportation conformity analyses that 

would allow future decreases in NOX

emissions from on-road mobile sources 

to offset any on-road increases in direct 

PM2.5 emissions. The State is proposing 

to use a 6.5 to 1 NOX to PM2.5 ratio for 

the 1997 annual PM2.5 NAAQS. This 

ratio was derived by performing a 

sensitivity analysis based on a 30 

percent reduction of NOX or PM2.5

emissions and calculating the 

corresponding effect on design values at 

sites in Bakersfield and Fresno. 

To ensure that the trading mechanism 

does not affect the ability of the San 

Joaquin Valley to meet the NOX budget, 

the NOX emissions reductions available 

to supplement the PM2.5 budget would 

be only those remaining after the NOX

budget has been met.188 The Plan also 

provides that the San Joaquin Valley 

MPOs shall clearly document the 

calculations used in the trading, along 

with any additional reductions of NOX

and PM2.5 emissions in the conformity 

analysis. 

3. The EPA’s Evaluation and Proposed 

Action 

The EPA generally first conducts a 

preliminary review of budgets 

submitted with an attainment or 

maintenance plan for PM2.5 for 

adequacy, prior to taking action on the 

plan itself, and did so with respect to 

the PM2.5 budgets in the 2018 PM2.5

Plan. On June 18, 2019, the EPA 

announced the availability of the 2018 

PM2.5 Plan with MVEBs and a 30-day 

public comment period. This 

announcement was posted on the EPA’s 

Adequacy website at: https://

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189 40 CFR 93.118(e)(4). 

190 40 CFR 93.120(a)(3). 

191 40 CFR 93.120(a)(2). 

192 Id. 

193 40 CFR 93.120(a)(1). 

194 General Preamble, 13539 and 13541–13542. 

transportation/state-implementationplans-sip-submissions-currently-underepa. The comment period for this 

notification ended on July 18, 2019. We 

did not receive any comments during 

this comment period. 

We have reviewed the motor vehicle 

emissions budgets in the 2018 PM2.5

Plan and find that, because we are 

proposing to disapprove the attainment 

demonstration and related elements of 

the SJV PM2.5 Plan for purposes of the 

1997 annual PM2.5 NAAQS based on the 

area’s failure to attain by the State’s 

projected attainment date, the budgets 

cannot be consistent with the applicable 

requirements for RFP and attainment of 

the 1997 annual PM2.5 NAAQS. 

Therefore, we are proposing to find that 

the motor vehicle emissions budgets do 

not meet applicable statutory and 

regulatory requirements, including the 

adequacy criteria specified in the 

transportation conformity rule.189 As 

discussed earlier in sections IV.C, IV.D, 

and IV.E, we are proposing to 

disapprove the Plan’s five percent, 

attainment, and RFP demonstrations. In 

addition, because we are proposing to 

disapprove the five percent and RFP 

demonstrations, the budgets are not 

consistent with the applicable 

requirements for the five percent annual 

reductions and RFP. Therefore, we are 

proposing to disapprove the budgets in 

the SJV PM2.5 Plan. Our proposed 

disapproval relates only to the 1997 

annual PM2.5 NAAQS, and does not 

affect the status of the budgets for the 

1997 24-hour PM2.5 NAAQS or the 

previously-approved budgets for the 

2006 PM2.5 NAAQS and related trading 

mechanism, which remain in effect for 

those PM2.5 NAAQS. Because we are 

disapproving the attainment and RFP 

demonstrations, the budgets are not 

eligible for a protective finding.190

If our proposed disapproval of the 

budgets is finalized, upon the effective 

date of our final rule, the area would be 

subject to a conformity freeze under 40 

CFR 93.120 of the transportation 

conformity rule. No new transportation 

plan, transportation improvement 

program (TIP), or project may be found 

to conform until the State submits 

another control strategy implementation 

plan revision fulfilling the same CAA 

requirements, the EPA finds the budgets 

in the revised plan adequate or approves 

the budgets, the MPO makes a 

conformity determination for the new 

budgets, and the U.S. Department of 

Transportation makes a conformity 

determination.191 In addition, only 

transportation projects outside of the 

first four years of the current 

conforming transportation plan and TIP 

or that meets the requirements of 40 

CFR 93.104(f) during the resulting 

conformity freeze may be found to 

conform until California submits a new 

attainment plan for the 1997 annual 

PM2.5 NAAQS and (1) the EPA finds the 

submitted budgets adequate per 40 CFR 

93.118 or (2) the EPA approves the new 

attainment plan and conformity to the 

new plan is determined.192

Furthermore, if, as a result of our final 

disapproval action, the EPA imposes 

highway sanctions under section 

179(b)(1) of the Act two years from the 

effective date of our final rule, then the 

conformity status of the transportation 

plan and TIP will lapse on that date and 

no new transportation plan, TIP, or 

project may be found to conform until 

California submits a new plan for the 

1997 annual PM2.5 NAAQS, and 

conformity to the plan is determined.193

H. Nonattainment New Source Review 

Requirements Under CAA Section 

189(e) 

CAA section 189(e) specifically 

requires that the control requirements 

applicable to major stationary sources of 

direct PM2.5 also apply to major 

stationary sources of PM2.5 precursors, 

except where the Administrator 

determines that such sources do not 

contribute significantly to PM2.5 levels 

that exceed the standards in the area.194

The control requirements applicable to 

major stationary sources of direct PM2.5

in a Serious PM2.5 nonattainment area 

include, at minimum, the requirements 

of a nonattainment NSR permit program 

meeting the requirements of CAA 

sections 172(c)(5) and 189(b)(3). As part 

of our April 7, 2015 final action to 

reclassify the San Joaquin Valley area as 

Serious nonattainment for the 1997 

PM2.5 standards, we established a May 

7, 2016 deadline for the State to submit 

nonattainment NSR SIP revisions 

addressing the requirements of CAA 

sections 189(b)(3) and 189(e) of the Act 

for the 1997 PM2.5 NAAQS. 

California submitted nonattainment 

NSR SIP revisions to address the 

subpart 4 requirements for the San 

Joaquin Valley Serious PM2.5

nonattainment area on November 20, 

2019. We are not proposing any action 

on this submission at this time. We will 

act on this submission through a 

separate rulemaking, as appropriate. 

V. Proposed Action 

For the reasons discussed in this 

proposed rule, under CAA section 

110(k)(3), the EPA is proposing to 

approve in part and disapprove in part 

the portions of the SJV PM2.5 Plan that 

pertain to the 1997 annual PM2.5

NAAQS for the San Joaquin Valley 

nonattainment area as follows: 

(1) We are proposing to approve the 

2013 base year emissions inventories as 

meeting the requirements of CAA 

section 172(c)(3) and 40 CFR 51.1008; 

and 

(2) We are proposing to disapprove 

the following elements: 

(a) The precursor demonstration as 

not meeting the requirements of 40 CFR 

51.1006, 

(b) The BACM/BACT demonstration 

as not meeting the requirements of CAA 

section 189(b)(1)(B) and 40 CFR 

51.1010, 

(c) The five percent demonstration as 

not meeting the requirements of CAA 

section 189(d) and 40 CFR 51.1010(c), 

(d) The attainment demonstration as 

not meeting the requirements of CAA 

sections 189(d) and 179(d) and 40 CFR 

51.1011(b), 

(e) The RFP demonstration as not 

meeting the requirements of CAA 

sections 172(c)(2) and 171(1) and 40 

CFR 51.1012, 

(f) The quantitative milestone 

demonstration as not meeting the 

requirements of CAA section 189(c) and 

40 CFR 51.1013, 

(g) The contingency measures as not 

meeting the requirements of CAA 

section 172(c)(9) and 40 CFR 51.1014, 

and 

(h) The motor vehicle emissions 

budgets as not meeting the requirements 

of CAA section 176(c) and 40 CFR 

93.118(e)(4). 

A. Effect of Finalizing the Proposed 

Disapproval Actions 

If we finalize disapprovals of the 

precursor demonstration, BACM/BACT 

demonstration, five percent 

demonstration, attainment 

demonstration, RFP and milestone 

demonstrations, motor vehicle emission 

budgets, or contingency measures, the 

offset sanction in CAA section 179(b)(2) 

will be applied in the San Joaquin 

Valley area 18 months after the effective 

date of such final disapproval. For new 

or modified major stationary sources in 

the area, the ratio of emission 

reductions to increased emissions shall 

be at least 2 to 1. The highway funding 

sanctions in CAA section 179(b)(1) will 

apply in the area six months after the 

offset sanction is imposed. Neither 

sanction will be imposed if California 


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195See 40 CFR 52.31, which sets forth in detail 

the sanctions consequences of a final disapproval. 

196 83 FR 62720. 

197 Id. 

198See 40 CFR 93.120(a). 

199 81 FR 84481, 84482 (November 23, 2016) 

(final EPA action determining that the San Joaquin 

Valley had failed to attain the 1997 PM2.5 NAAQS 

by the December 31, 2015 Serious area attainment 

date). 

submits and we approve SIP revisions 

meeting the applicable CAA 

requirements prior to the 

implementation of the sanctions.195

In addition to the sanctions, CAA 

section 110(c)(1) provides that the EPA 

must promulgate a federal 

implementation plan (FIP) addressing 

any disapproved elements of the plan 

two years after the effective date of 

disapproval unless the State submits, 

and the EPA approves, the required SIP 

submittal. As a result of the EPA’s 

December 6, 2018 determination that 

California had failed to submit the 

required attainment plan for the 1997 

PM2.5 NAAQS, among other required 

SIP submissions for the San Joaquin 

Valley,196 the EPA is already subject to 

a statutory deadline to promulgate a FIP 

for this purpose no later than two years 

after the effective date of that 

determination.197

Furthermore, if we take final action 

disapproving the SJV PM2.5 Plan, a 

conformity freeze will take effect upon 

the effective date of any final 

disapproval (usually 30 days after 

publication of the final action in the 

Federal Register). A conformity freeze 

means that only projects in the first four 

years of the most recent RTP and TIP 

can proceed. During a freeze, no new 

RTPs, TIPs, or RTP/TIP amendments 

can be found to conform.198

Finally, if the EPA takes final action 

on the SJV PM2.5 Plan as proposed, 

California will be required to develop 

and submit a revised plan for the San 

Joaquin Valley area that addresses the 

applicable CAA requirements, including 

the requirements of CAA section 189(d). 

In accordance with sections 179(d)(3) 

and 172(a)(2) of the CAA, the revised 

plan must demonstrate attainment as 

expeditiously as practicable and no later 

than five years from the date of the 

EPA’s determination that the area failed 

to attain (i.e., by November 23, 2021), 

except that the EPA may extend the 

attainment date to a date no later than 

10 years from the date of this 

determination (i.e., to November 23, 

2026), considering the severity of 

nonattainment and the availability and 

feasibility of pollution control 

measures.199

The EPA is soliciting public 

comments on the issues discussed in 

this proposed rule. We will accept 

comments from the public on this 

proposal for the next 30 days. 

VI. Incorporation by Reference 

In this document, the EPA is 

proposing to amend regulatory text that 

includes incorporation by reference. As 

explained in section IV.F.3 of this 

preamble, the EPA is proposing to 

remove section 5.7.3 of SJVUAPCD Rule 

4901 from the California State 

Implementation Plan, which is 

incorporated by reference in accordance 

with the requirements of 1 CFR part 51. 

VII. Statutory and Executive Order 

Reviews 

Additional information about these 

statutes and Executive Orders can be 

found at http://www2.epa.gov/lawsregulations/laws-and-executive-orders. 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

This action is not a significant 

regulatory action and was therefore not 

submitted to the Office of Management 

and Budget (OMB) for review. 

B. Paperwork Reduction Act (PRA) 

This action does not impose an 

information collection burden under the 

PRA because this proposed SIP 

disapproval, if finalized, will not inand-of itself create any new information 

collection burdens but will simply 

disapprove certain State requirements 

for inclusion in the SIP. 

C. Regulatory Flexibility Act (RFA) 

I certify that this action will not have 

a significant economic impact on a 

substantial number of small entities 

under the RFA. This action will not 

impose any requirements on small 

entities. This proposed SIP disapproval, 

if finalized, will not in-and-of itself 

create any new requirements but will 

simply disapprove certain state 

requirements for inclusion in the SIP. 

D. Unfunded Mandates Reform Act 

(UMRA) 

This action does not contain any 

unfunded mandate as described in 

UMRA, 2 U.S.C. 1531–1538, and does 

not significantly or uniquely affect small 

governments. This action proposes to 

disapprove pre-existing requirements 

under state or local law and imposes no 

new requirements. Accordingly, no 

additional costs to state, local, or tribal 

governments, or to the private sector, 

result from this action. 

E. Executive Order 13132: Federalism 

This action does not have federalism 

implications. It will not have substantial 

direct effects on the states, on the 

relationship between the national 

government and the states, or on the 

distribution of power and 

responsibilities among the various 

levels of government. 

F. Executive Order 13175: Coordination 

With Indian Tribal Governments 

This action does not have tribal 

implications, as specified in Executive 

Order 13175, because the SIP revision 

that the EPA is proposing to disapprove 

would not apply on any Indian 

reservation land or in any other area 

where the EPA or an Indian tribe has 

demonstrated that a tribe has 

jurisdiction, and will not impose 

substantial direct costs on tribal 

governments or preempt tribal law. 

Thus, Executive Order 13175 does not 

apply to this action. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

The EPA interprets Executive Order 

13045 as applying only to those 

regulatory actions that concern 

environmental health or safety risks that 

the EPA has reason to believe may 

disproportionately affect children, per 

the definition of ‘‘covered regulatory 

action’’ in section 2–202 of the 

Executive Order. This action is not 

subject to Executive Order 13045 

because this proposed SIP disapproval, 

if finalized, will not in-and-of itself 

create any new regulations but will 

simply disapprove certain state 

requirements for inclusion in the SIP. 

H. Executive Order 13211: Actions That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This action is not subject to Executive 

Order 13211 because it is not a 

significant regulatory action under 

Executive Order 12866. 

I. National Technology Transfer and 

Advancement Act (NTTAA) 

Section 12(d) of the NTTAA directs 

the EPA to use voluntary consensus 

standards in its regulatory activities 

unless to do so would be inconsistent 

with applicable law or otherwise 

impractical. The EPA believes that this 

action is not subject to the requirements 

of section 12(d) of the NTTAA because 

application of those requirements would 

be inconsistent with the CAA. 


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38674 Federal Register / Vol. 86, No. 138 / Thursday, July 22, 2021 / Proposed Rules 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Population 

The EPA lacks the discretionary 

authority to address environmental 

justice in this rulemaking. 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Ammonia, 

Incorporation by reference, 

Intergovernmental relations, Nitrogen 

dioxide, Particulate matter, Reporting 

and recordkeeping requirements, Sulfur 

dioxide, Volatile organic compounds. 

Authority: 42 U.S.C. 7401 et seq. 

Dated: July 12, 2021. 

Deborah Jordan, 

Acting Regional Administrator, Region IX. 

[FR Doc. 2021–15551 Filed 7–21–21; 8:45 am] 

BILLING CODE 6560–50–P 


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